Have there been studies done on "advanced users"? I'm an advanced user and I think mouse based interfaces are great when mixed sensibly with keyboard shortcuts and command search (like VSCode's Ctrl-Shift-P).
I'm not going to ever use the Edit->Copy menu but I'm also not going to learn the shortcut to click the Ublock origin button in Chrome, which I do maybe once a month.
Do you have any evidence for your assertion? It sounds like snobbery.