I use both GNOME and KDE. I do have a system tray, but it’s for a single program: fcitx-mozc. If I didn’t need to build ibus-mozc from source, I would just use that. iBus IMEs get their own spot in the top right without needing appindicators. That being said, I don’t need the system tray either as I can just switch between Japanese and English with CTRL+SPACE. But it’s nice to have some kind of constant indication what IME I’m using.
On the subject of a dock, though, I love the way GNOME completely separates it from the workspace. It just takes up space and I don’t have any utility for it. Windows and macOS only allow you to hide the dock; not remove it completely. I’ve accidentally opened the dock by moving my cursor to the corner of the screen way too many times and it is sooo annoying. This never happens on GNOME because it’s just not possible.
Also I tend to think it’s been designed for people who are more comfortable using a keyboard. I’m mostly a mouse person.
That’s absolutely true, but you can navigate GNOME completely with a mouse. If you’re on a laptop, you can use the trackpad to flick between workspaces with three fingers. Every aspect of the GNOME desktop is navigable with the mouse, including the Activity Overview. GNOME’s workflow changed the way I use computers.
One thing I miss from KDE is GNOME’s tiling. KDE’s is far more inconsistent. But there are a lot of things I like more about KDE too. I use it in basically the same way as GNOME.