If the Windows key didn’t exist, Ctrl Alt would work just as well and wouldn’t require anything else to remember because all OS level shortcuts would be Ctrl Alt shortcuts that wouldn’t conflict with any applications.
Using Ctrl Alt would also be faster and more accessible because they are on the right and left instead of the current Super key (Windows) being only on the left.
If the Windows key didn’t exist, Ctrl Alt would work just as well and wouldn’t require anything else to remember because all OS level shortcuts would be Ctrl Alt shortcuts that wouldn’t conflict with any applications.
Using Ctrl Alt would also be faster and more accessible because they are on the right and left instead of the current Super key (Windows) being only on the left.
Sometimes a key gets bound in all regular modifiers so you really need another one.
For example I use Super+F for fullscreen because Ctrl+F, Alt+F and Ctrl+Alt+F are all taken in this or that program.
Oh and btw the right-hand Alt is usually AltGr not regular Alt for non-English countries, it’s used for composing diacritics.
Pedantic point but of the major English QWERTY layouts, US has two Alts, UK has AltGr on the right
It doesn’t matter what it says on the key, it gets mapped to AltGr so it can’t be used as Alt.