[QUESTION] Flatpak or AUR?

I’ve been using arch for a while now and I always used Flatpaks for proprietary software that might do some creepy shit because Flatpaks are supposed to be sandboxed (e.g. Steam). And Flatpaks always worked flawlessly OOTB for me. AUR for things I trust. I’ve read on the internet how people prefer AUR over Flatpaks. Why? And...