Cmd+~ switches windows of a given app in case you didn't know (not disagreeing with you but it is one shortcut I find super useful and it helps switch windows).
This is why I regard ChromeOS with fear. Because it really does feel like everything is just converging on the browser as the OS, and a browser is not a goddamn OS.
I have a non-ANSI keyboard so tilde is in a super weird place for that (next to left shift). I swapped the shortcut to Option+Tab, makes much more intuitive sense.