@Paris_Nicolaides It's not so much a question of how busy our schedules are as how stable our lives are on a timescale of months. 72 hours (or even only 24 hours) is fine for making our moves under our normal circumstances, and those circumstances will determine what time controls we choose as you point out. But suppose unforeseen circumstances arise which turn our life on its head. For example, suppose we are suddenly forced to move house unexpectedly. When we're up to our eyeballs with packing boxes, arranging temporary accommodation, and travelling to and fro between the old and new homes, making our moves in our correspondence games will suddenly take a back seat in our priority list.
I do think that whatever special measures among the suggestions above are introduced, they should be voluntary. It should remain possible to start games where no vacation, time banks or other forms of timeout protection is permitted. After all, it's clear that many correspondence players don't want anything to do with that.
For myself, though, the lack of any sort of vacation time here is the reason why I virtually never play Correspondence on this site despite it being my favourite form of the game.