Automatics are, ultimately, for people who failed their manual test five times aren't they?
I'm sure we'll lose manual cars soon as part of the general trend towards turning us all into brains in jars. As for 'freeing up mental space' I think the opposite is true, and having to physically do stuff like changing gear keeps you more focussed on what you're doing than just pressing the go button, setting the cruise control and then telling your digital assistant to play your classical chillout mix or whatever stupid shit people talk to cars for.