I've bounced around alot, have numerous distributions on my Proxmox Hypervisor, but my favorite daily driver, for a really old computer, is ( MX Linux ) I've twice tried other distros to see if I could improve upon the stability and performance, as well as the very convenient availability of a feature rich KDE Desktop environment, and I came back to MX twice now. When I get a new fast computer, I'll switch to Qubes OS, for it's built-in hypervisor and security/privacy and isolation features, but until then, I'll stick with MX.
IMHO, there are excellent reasons why MX ranks highest. I think it's original roots in AntiX with the elimination of systemd has afforded it a substantial advantage over stock-standard Debian, my last daily driver which always had performance issues. With MX, on same hardware, system lock ups are far less frequent when the system is overtaxed.
Funny, flatpak works on MX, but it kills performance. I launch any flatpak program and it's literally up to five minutes to launch. After re-imaging and using AppImages instead, it's blazing fast. There must be something about the way MX implements flatpaks that screws the pooch.