Small and pointless delays. Such as menus 'shoowshing' in through animations. It may only be very short animations, but when you've seen that 1 second animation thousands of times, it fucking adds up. Thing you could do by muscle memory in under 2 seconds is dragged out to 6+ seconds because you've got to wait for the menus to be pretty. It's a tiny grievance, but one that constantly haunts me.