One of the greatest UX sins you can commit, is to override common, well-understood keyboard shortcuts, like Ctrl-Z.

It's kinda hard to satisfy everyone though since you have the 'vi' and 'emacs' groups as well as 'tmux' vs 'screen'. (not even talking about obscure configs like this terminal vs other terminal or tiling window managers)

I can't actively remember the amount of hotkeys I have in my muscle memory.

Like on macOS, where Ctrl+Z almost nowhere is a shortcut for anything.

I'm looking at you, QuickBooks.

THIS. So tired of outlook web using CTRL+R for reply instead of reload page, forget it every damn time

Or Ctrl+z to undo and Ctrl+Shift+z to redo.