even windows have better UI. on a Mac you can't even alt-tab between two terminal windows. ridiculous.
There's simply a more sharply defined distinction between applications and windows. Cmd-Tab is for application switching.
if the user wants to move to a terminal window they have open in the background, which key combination do they press? alt+tab or alt+backtick? they have to stop and actively think about which current window is highlighted. is it the browser? or another terminal? this completely kills the action fluency of a keyboard shortcut.
This is generally a non-issue, but even if you are getting tripped up consistently, the OS literally tells you at all times what application currently has focus