If you hate reading like me, here’s the summary:
Open terminal (ctrl+alt+T) and type:
yay -S chromium-widevine
This will download a .deb package of Chromium (I assume because of dependencies) and then install Widevine. This will NOT INSTALL the Chromium web browser.
For context of how I came about this solution (spoiler, nothing genius): Widevine is needed to play DRM/Private/paid content on the browsers. It was a known issue that sometimes this could’ve been by default, disabled. For example on Firefox, sometimes you had to check the box of “Play DRM content”.
Going to edge://flags however, wasn’t the solution because for some reason, hardware encode/decode, hardware video acceleration, widevine and other stuff is “unavailable on your platform”, so you couldn’t enable/disable it from there.
According to a comment by the package uploader in the AUR:
Scimmia commented on 2020-05-18 20:20
ATTENTION:
This package is no longer needed for Chromium, it can download the component itself. With Chromium 81, you can either use this or let it download the component, but when Chromium 83 is updated in the Arch repos, it will ignore this package all together.
I’ll maintain this package for a while for the other systems that use it.
As you can see, widevine component should now comes directly with Chromium and because of this, I assumed chromium-based browsers as well, but maybe it was just Chromium browser and not the engine (this is perhaps why it has to download the .deb package).
This wasn’t “obvious” for my newbie mind because Firefox could play it just fine, and not just Endeavour, other distros as well, both Arch and Debian based (that is why I kept it installed). So I thought perhaps it was Edge’s fault alone. In a Ubuntu forum, people said to use the switch user agent string extension and that should work (switch to chrome) - however, not understanding how that works entirely, I got the extension but when you click on things it’s like… super old. It has Internet Explorer and Windows Phone, as well as Firefox 33. I didn’t want to mess with that and maybe you could turn it off (aka disable the extension) to go back to normal but what are you going to do, switch it back and forth? There’s no point. So I had my first idea as arch/endeavour OS user: “Someone must’ve done it!”. It occurred to me to search pacman and yay (repos and AUR) for widevine, see if there was something. And so here we are. Once you install the component, you don’t need to do anything else, not even enable the flags (which is still unavailable). Just close the browser and open it again just in case. Enjoy your Netflix watching! Hilariously enough it works MUCH better than on Windows. Pausing and pressing play, changing tabs or pausing for a long time don’t break the thing or make it work weird (at least that’s what happened to me through several versions of windows 10, 11 and different fresh installs). Hopefully this helped you (and maybe this solution is also needed for other browsers, except Vivaldi which has its own component in AUR).