Debian is just not going to have access to as much up to date software as it probably needs, even with testing back ports, to run well. I say this as a very long time Debian user that is really struggling in this day and age to find a place for Debian among my devices at this point.
Out of curiosity, what distribution have you been using lately instead of Debian?
Anecdotally, I've been using Fedora Workstation for a few years already, and my Steam + Proton Experimental experience has been fantastic with an AMD GPU using the drivers that come with the kernel.
Although I must admit, I miss having a Debian-based distribution sometimes, because in some situations I can't find rpm packages for more specific things I'm trying to do in my system. The problem is I just don't know any other distribution that's not Debian Testing that could work like Fedora Workstation but with .deb packages.
I add flathub.org and remove the fedora flatpak repo. The few other things I need are in copr/terra, but honestly they are very rare. I think I have maybe 1 piece of software per thing that doesn't release a native .rpm (ghostty is one)
