This generally isn't my experience with GNOME.
You have to install an extension to get a dock at all.
No, there's an auto-hiding dock built-in. Pressing the Super key acts like better version of Apple's Expose feature: it shows the windows you have open, auto-opens the dock, and focuses the application launcher search bar so you can just start typing and launch an app.
You had to install a system tray extension
I'm sure you needed to at some point, but (as you mention), that's no longer the case: it's built in by default.
clipboard manager
If you mean clipboard history... That's true. Although macOS doesn't have a built-in clipboard history viewer either, and I never particularly missed having one. There are plenty of GNOME extensions with clipboard history if you want one.
Generally speaking I like GNOME much more than KDE, since GNOME's gesture support is much better than KDE's. I also personally dislike Windows-style infinitely-nesting-menu taskbars, which is what KDE uses, whereas GNOME is more macOS-like (although it has its own, IMO slightly cleaner style... And of course, it's much more modifiable than macOS).
You have to install an extension to get a dock at all.
No, there's an auto-hiding dock built-in. Pressing the Super key acts like better version of Apple's Expose feature: it shows the windows you have open, auto-opens the dock, and focuses the application launcher search bar so you can just start typing and launch an app.
You had to install a system tray extension
I'm sure you needed to at some point, but (as you mention), that's no longer the case: it's built in by default.
clipboard manager
If you mean clipboard history... That's true. Although macOS doesn't have a built-in clipboard history viewer either, and I never particularly missed having one. There are plenty of GNOME extensions with clipboard history if you want one.
Generally speaking I like GNOME much more than KDE, since GNOME's gesture support is much better than KDE's. I also personally dislike Windows-style infinitely-nesting-menu taskbars, which is what KDE uses, whereas GNOME is more macOS-like (although it has its own, IMO slightly cleaner style... And of course, it's much more modifiable than macOS).