I hate all the cruft in my home directory, but I also hate when stuff suddently stop working after an update, or when all the documentation online talks about something that doesn’t work on my system or is not there anymore. Developers are the ones that will have to deal with people with these issues, so I can see why they are reluctant to implement the naive solutions that some ask for.

Not sure if Discord is the best example here, as it didn’t support the screen capture portal for a very long time.

If you distribute your app via Flatpak, what benefit is there over “disk space” (irrelevant for all but embedded devices)

Everyone always focuses on disk space, but IMO the real issue is download size, especially when you update a bunch of flatpaks together.

I still prefer the upstream flatpaks over Fedora’s though.

Software implementations of those features is often slower, and runtime checking can often be too expensive compared to the gains.

since it seems like nobody but cachy or custom kernel runs anything but V1

Gentoo offers x86_64-v4 binary builds too.

There was a proposal for Fedora too, though it was ultimately rejected.

Ultimately the gains right now seem to be only 1-3%, though that might also be because there’s not much demand for these kind of optimizations. If more distros enable them they might become more widespread and the benefits might increase too. It’s a chicken-egg problem though.