Here’s a thing, Sony has something called open devices.
https://developer.sony.com/develop/open-devices/get-started/supported-devices-and-functionality/
You can install the latest Android AOSP on them. LineageOS is also compatible. All sanctioned by Sony, as in they officially provide the tools to unlock the bootloader.
I’ve come upon this after I read this post here and checked the XA2 more closely.
Now I’m considering buying a used Xperia XA2 for myself too.