I am specifically zeroing in on that because there just aren't that many good "bosses" out there, and even fewer great leaders...as much as most bosses think they may be good. If you do have a great boss that takes the time and energy to do mentorship, wonderful! But that leaves us with the rest of the workforce that has average and bad managers...I would bet that remote outcomes for that part of the workforce are not great.

No, but at least in person it's easier and much more natural to facilitate mentorship opportunities for yourself if your boss isn't so good.