A recent blog post in the Apple fanboy world posited that Apple has slow, non-user-adjustable animations that make the OS feel slow. That's basically why a user thinks KDE or Gnome is snappier. It has nothing to do with CPU architecture.
I still have an Intel Mac and it doesn't feel significantly slower than one with Apple silicon.
Last time I installed Gnome I had to install an extension to remove the 150ms delay on alt-tabbing that is present even when animations are disabled. It became snappy after that.
I still have an Intel Mac and it doesn't feel significantly slower than one with Apple silicon.