I wouldn’t say it’s lazy at all. I’d say it’s management of a human’s mental capacity. If you can only fly by memorising numbers with the autothrust off on a nice day, what hope do you have when it’s something serious? Can you remember every power setting for each emergency at each weight and each config? You should be thinking about something else.
Set the attitude, check the speed trend, make an appropriate adjustment Start sorting out your other problems, in a bit flick back to trend arrow, check again. Refine and go back to sorting out the problem. Works on any aircraft.