I will speak for myself, of course. It was not “constant” of course, but it happened. Now, this may not be an issue when you can afford 10 hours sessions, but when you have 1 hour or so sessions, given the time it takes to form or enter a group and enter the dungeon, a leave mid to end key means a completely wasted session.
Having a lot of spare time is not a skill, you have it or you don’t. If you don’t there’s not much you can do about it and group activities like M+ become a nightmare, also because unlike random BGs for example (that I also ditched because of waiting times) you can’t do anything else while trying to form or enter a group for M+.