About the Fedora Gnome vs EndeuvourOS KDE... the issue here isn't Gnome. It's actually Fedora. In my testing on a similar hardware (also Core M3 and 4gb RAM), Arch-based distros was the best with low RAM. And I tried like, probably 50 distros since last year... Gnome on my HW with Arch, is as fast as KDE, and use less memory than KDE (in theory, I know RAM is a complicated subject). Why fedora is problematic on low e…
Expected the difference with Ubuntu as it packs more out of the box for the enterprise behaviours, not so much with Fedora. I've had no freezes, faster startup and shutdown, generally more responsive desktop etc. with Arch.
Generally, though a rolling release it also has fewer moving parts as well - only having to deal with the main repo + flatpak (and a select few AUR pkgbuilds) is nice compared to Ubuntu where I had to layer deb repos + PPAs + flatpak + brew to get my tooling in place without having to script my own git-driven installers.
One thing that tripped me up on any distro - the defaults for TLP (vs power profile daemon) seem hyper conservative wrt performance, probably by design. I never bothered digging in, just switched back to PPD, but it definitely prioritises power savings above all else.