A compiler to simplify,one of the main uses is for local LLM/VM but it can be quite a lot of different things, I also have it but it’s nowhere near 5Gb…
❯ LANG=C paru -Ps
paru v2.1.0 - libalpm v15.0.0
===========================================
Total installed packages: 854
Aur packages: 1
Repo packages: 853
Explicitly installed packages: 246
Total Size occupied by packages: 6.88 GiB
===========================================
Ten biggest packages:
jdk-openjdk: 499.68 MiB
signal-desktop: 427.35 MiB
ungoogled-chromium-bin: 389.87 MiB
noto-fonts-extra: 331.76 MiB
noto-fonts-cjk: 298.79 MiB
rust: 263.22 MiB
linux-zen-headers: 248.30 MiB
ttf-jetbrains-mono-nerd: 222.51 MiB
gcc: 208.47 MiB
llvm-libs: 150.01 MiB
===========================================
There is not too much installed on this particular system I guess.
Of course, AppImages are not shown in this output; OnlyOffice and Joplin would be in my top ten by size if it did.
~/Applications
❯ eza -l --no-permissions --no-user --no-time *.AppImage
155M Joplin.AppImage
118M LibreWolf.AppImage
450M OnlyOffice.AppImage
:$ LANG=C yay -Ps
==> Yay version v12.5.0
===========================================
==> Total installed packages: 1364
==> Foreign installed packages: 0
==> Explicitly installed packages: 228
==> Total Size occupied by packages: 9.7 GiB
==> Size of pacman cache /var/cache/pacman/pkg/: 3.4 GiB
==> Size of yay cache /home/marcs/.cache/yay: 2.3 MiB
===========================================
==> Ten biggest packages:
nvidia-utils: 886.1 MiB
noto-fonts-extra: 331.8 MiB
noto-fonts-cjk: 298.8 MiB
lib32-nvidia-utils: 276.6 MiB
firefox: 263.6 MiB
occt: 262.1 MiB
qt6-webengine: 258.6 MiB
linux-headers: 244.7 MiB
gcc: 208.5 MiB
inkscape: 173.4 MiB
===========================================
$ expac -HM "%m|%n" | column -t -s'|' | sort -n | tail -n10
215.65 MiB virtualbox
237.89 MiB go
244.74 MiB linux-headers
258.62 MiB qt6-webengine
263.22 MiB rust
263.64 MiB firefox
264.04 MiB emacs
264.87 MiB firefox-developer-edition
406.88 MiB vscodium-bin
415.05 MiB libreoffice-fresh
$ yay -Ps
==> Yay version v12.5.0
===========================================
==> Total installed packages: 1415
==> Foreign installed packages: 2
==> Explicitly installed packages: 368
==> Total Size occupied by packages: 10.0 GiB
==> Size of pacman cache /var/cache/pacman/pkg/: 2.2 GiB
==> Size of yay cache /home/manuel/.cache/yay: 4.0 KiB
===========================================
==> Ten biggest packages:
libreoffice-fresh: 415.1 MiB
vscodium-bin: 406.9 MiB
firefox-developer-edition: 264.9 MiB
emacs: 264.0 MiB
firefox: 263.6 MiB
rust: 263.2 MiB
qt6-webengine: 258.6 MiB
linux-headers: 244.7 MiB
go: 237.9 MiB
virtualbox: 215.7 MiB
[erik@erik-um5606wa ~]$ yay -Ps
==> Yay version v12.5.0
===========================================
==> Total installed packages: 1325
==> Foreign installed packages: 15
==> Explicitly installed packages: 262
==> Total Size occupied by packages: 11.6 GiB
==> Size of pacman cache /var/cache/pacman/pkg/: 6.4 GiB
==> Size of yay cache /home/erik/.cache/yay: 8.4 GiB
===========================================
==> Ten biggest packages:
wine: 1.5 GiB
vivaldi: 417.2 MiB
libreoffice-fresh: 415.1 MiB
noto-fonts-extra: 331.8 MiB
vtk: 308.8 MiB
noto-fonts-cjk: 298.8 MiB
proton-pass-bin: 296.1 MiB
betterbird-bin: 271.0 MiB
firefox: 263.6 MiB
qt6-webengine: 258.6 MiB
===========================================
You can see which installed packages need a package, for example:
yay -Qii jdk21-openjdk | grep "Required By"
# or
expac %N jdk21-openjdk
They might also be an optional dependency. Or you might have a system language other than English. Then use:
$ LANG=C pacman -Qi jre-openjdk | grep -E "(Required By|Optional For)"
EDIT: Sorry, took it from my system. So it shows “jre-openjdk” instead of your “jdk21-openjdk”. JRE is the Java Runtime Environment, JDK is the Development Kit.
┌╼ [ajgringo619@eos-xfce-host]╾╼[/home/ajgringo619]╾╼[23:23:47]
└─╼ $ yay -Ps
==> Yay version v12.5.0
===========================================
==> Total installed packages: 1242
==> Foreign installed packages: 4
==> Explicitly installed packages: 324
==> Total Size occupied by packages: 11.1 GiB
==> Size of pacman cache /var/cache/pacman/pkg/: 3.3 GiB
==> Size of yay cache /tmp/yay-builddir: 40.0 B
===========================================
==> Ten biggest packages:
nvidia-utils: 886.1 MiB
visual-studio-code-bin: 432.7 MiB
vivaldi: 417.2 MiB
libreoffice-fresh: 415.1 MiB
noto-fonts-extra: 331.8 MiB
noto-fonts-cjk: 298.8 MiB
proton-pass-bin: 296.1 MiB
electron37: 282.2 MiB
lib32-nvidia-utils: 276.6 MiB
proton-mail-bin: 261.7 MiB
===========================================
This is very misleading since it doesn’t include Steam (currently at 286 GB).
True. And with expac:
expac "%N %o" jre-openjdk
Yeah, it was a quickshot. Self-built or manually installed software, AppImages, Flatpaks and Snaps are missing here.
To find the real “space wasters”, probably better use ncdu -x /, maybe even with sudo.
--- / --------------------------------------------------------------------------
. 56.1 GiB [###########] /timeshift
26.4 GiB [##### ] /backintime
24.8 GiB [#### ] /home
. 17.1 GiB [### ] /usr
. 10.1 GiB [# ] /var
. 1.6 GiB [ ] /opt
Or something using du—possibilities are endless… 
$ LC_ALL=C.UTF-8 sudo du -xh --max-depth=1 / | LC_ALL=C.UTF-8 sort -hr | head -n 11
Place your right index finger on the fingerprint reader
138G /
58G /timeshift
27G /backintime
25G /home
18G /usr
11G /var
1.7G /opt
13M /boot
12M /etc
6.9M /root
16K /lost+found
Still interesting what people use, and what space some packages take.
I’m definitely snapshot-crazy, for fear I might break something! 
$ yay -Qii jdk21-openjdk | grep “Required By”
Required By : keycloak
$ yay -Ss keycloak
extra/keycloak-archlinux-theme 1.5.1-1 (566.9 KiB 1.1 MiB) (Installed)
Keycloak Arch Linux theme
extra/keycloak 26.3.3-1 (138.0 MiB 163.2 MiB) (Installed)
Open Source Identity and Access Management For Modern Applications and Services
thought #1: I was shitfaced?
thought #2: keycloak is related to theming?
thought #3: see #1
According to the Arch wiki, it should be a web-based single sign-on solution. Looks like it brings in JDK, PostgreSQL and its own themes…
expac -H M '%m %n' | sort -rh | head -10
643.44 MiB electronmail-bin
480.97 MiB jdk11-openjdk
446.82 MiB mame
417.25 MiB vivaldi
282.24 MiB electron37
263.64 MiB firefox
258.62 MiB qt6-webengine
252.94 MiB thunderbird
208.47 MiB gcc
161.62 MiB linux-lqx
and
ls -sh1S .local/bin/*.AppImage
430M OnlyOffice.AppImage
136M Thorium-3.2.2.AppImage
[g@g-xps8940 ~]$ yay -Ps
==> Yay version v12.5.0
===========================================
==> Total installed packages: 1299
==> Foreign installed packages: 17
==> Explicitly installed packages: 245
==> Total Size occupied by packages: 14.7 GiB
==> Size of pacman cache /var/cache/pacman/pkg/: 8.3 GiB
==> Size of yay cache /home/g/.cache/yay: 4.0 KiB
===========================================
==> Ten biggest packages:
wine: 1.5 GiB
nvidia-utils: 886.1 MiB
openoffice-bin: 386.4 MiB
librewolf-bin: 373.1 MiB
chromium: 372.5 MiB
mullvad-vpn-beta-bin: 354.4 MiB
noto-fonts-extra: 331.8 MiB
zen-browser-bin: 323.5 MiB
vtk: 308.8 MiB
noto-fonts-cjk: 298.8 MiB
===========================================
[g@g-xps8940 ~]$
❯ LANG=C yay -Ps
==> Yay version v12.5.0
===========================================
==> Total installed packages: 1777
==> Foreign installed packages: 64
==> Explicitly installed packages: 387
==> Total Size occupied by packages: 26.3 GiB
==> Size of pacman cache /var/cache/pacman/pkg/: 53.1 MiB
==> Size of yay cache /home/lou/.cache/yay: 2.4 MiB
===========================================
==> Ten biggest packages:
obs-studio-tytan652-debug: 1.9 GiB
texlive-fontsextra: 1.7 GiB
wine: 1.5 GiB
onlyoffice-bin: 1019.2 MiB
jdk24-graalvm-ee-bin: 819.8 MiB
zoom: 784.8 MiB
apple-fonts: 555.9 MiB
dart: 497.7 MiB
visual-studio-code-bin: 432.7 MiB
libreoffice-fresh: 415.1 MiB
TIL people still use openoffice 
It works just fine for me. Thanks.
If it works, it works. I was just surprised is all.
Your Thorium the e-reader app? I used aur/thorium-reader-bin. (Could be that just unpacks the AppImage, though.)