It's bad everywhere. Every time I've upgraded Ubuntu on my old laptop, performance gets worse and worse because more and more junk keeps getting added. Absolutely maddening.
Is it the desktop environment or background stuff that’s getting worse for you? If the former: FWIW I was pleasantly surprised when I switched back to Kubuntu. KDE’s surprisingly resource efficient these days, actually seems pretty close to XFCE.
NixOS looks super cool, but it also looks too much like actual work. As a FreeBSD main for two decades, I've played that game already and have the (sadly, now long dead) tinderbox and poudriere installations to prove it.
