The Shift key on the keyboard is there, but it is not used most of the time, unless you are having a bad day and MUST YELL AT PEOPLE ON THE INTERNET! But fortunately we can use it in a different way and make our daily work a little easier.
On the one hand you can assign the Shift key under System Preferences > Keyboard > Modifier Keys. By default macOS at least offers you to replace the shift function with “Esc” – which became famous with the first Touch Bar MacBooks – or “alt” and similar. These settings are sufficient to log off the computer ergonomically and comfortably by shortcut.
But if you want to put other funkctions on the key, you need an additional program. You can choose between Shifted and Karabiner-Elements (formerly known as Seil). This gives you the possibility to assign different functions and actions to the key.
You get an extra key for macOS shortcuts!
Shifted is a bit easier and costs a small 5 dollars for the pro functions, Karabiner-Elements is free (a fair donation of course welcome) and much more powerful.
In any case, you can equip the actually fallow button with very practical and extensive functions in various ways. You have, so to speak, an extra key for your system-wide individual shortcut. If that is not practical.