My complaint with Gnome is just one, but it is overbearing: Gnome devs want to decide what is best for you, which stinks and goes against the very fundament of open software. But would not per se be a problem -- If they hadn't also decided that a bunch of things that are considered basic features that every other DE and even other OSes have implemented for the past 20 years are, in fact, unnecessary.
Consider the humble System Tray.
Gnome removed the System Tray in favour of a "Control Center". And the Control Center works really well -- For inbuilt Gnome stuff and applications that were written for Gnome. But stuff that is DE agnostic, or god forbid, ported over from another OS? Some of them expect a tray to be there. Have functionality that doesn't work without one. Or do work but are janky. Gnome doesn't offer a system tray. You have to install a third party extension, which would also be fine... Except every time Gnome updates every other third party extension breaks.
And like, sure, it's not Gnome Devs' job to ensure the operability of third party addons, but that you need them to begin with is a failure. Gnome's attitude towards everything seems to be "$#¨$ you, like just actually go &%$# yourself. You do things our way or you use something else. We have decided these things are useless, if you think they are necessary you are a $&@# and %$#$ you and the horse you rode in on"
As for my personal favourite DE? KDE Plasma. It's not something I'd ever recommend to a newcomer, but I like it precisely because of how many moving parts it has. I can make my system look, feel, and act just the way I like it. It's like the polar opposite of Gnome really.