I mostly stream to my Ally from my desktop via Sunshine - it can run almost anything at high settings on 1080p, and the Ally can be left on low power mode so the battery lasts forever.
I've left Windows installed on the Ally for maximum compatibility, but I'm playing around with the idea of a Linux distro because if I keep the desktop on Windows I can still play games that don't like Linux.
I use Windows 11 for my Ally but on my other machines I am transitioning to Linux Mint. I'll keep Windows 11 on my Ally for the compatibility with games and most importantly for me, emulators.