I'm not trying to convince you to like something you don't, and KDE is a fucking great suite of software.
However, it does sound like maybe you haven't used GNOME in quite a long time. It does have various customizations built in that are available to users through the settings UI these days, and "tweaks that barely work" isn't really a representative critique of the general ecosystem anymore.
GNOME's extension platform is very mature at this point, and I've personally used a bunch of the same extensions for years now spanning like 10 major releases of GNOME without issue. Yeah, the little fly-by-night extensions that get two point releases and then are abandoned don't work forever, but that's true of a lot of old software, and is probably a good thing, honestly.