(Commenting on a post about LineageOS)
I’m still embedded in the Google ecosystem on other devices, but I’ve used LineageOS (and its predecessor CyanogenMod) to resurrect my old Galaxy S4 – twice! It’s now functioning quite well as a backup phone with a kid’s profile for camera, games, etc.
I’d like to use it on a 2015 vintage Galaxy Tab A, but there don’t seem to be official images, which means I may need to figure out how to build it on my own.