Have you participated in rotating GMs?

[Batcathat]

The first benefit is that it keeps everyyone at the table on the same level, no hierarchies.

The second benefit is that it does provide both reason and a safe environment for new GMs to take their first steps.

The third reason it that it helps a lot against GM burnout because everyone gets regular, long breaks.

I can't say I've ever had a problem with a table being too hierarchical, but I suppose it might help someone with that issue (assuming it's specifically based on the GM having more power than the players).

As for the other reasons, I agree that it can be good to change GMs on occasion, whether it's to give the current GM a break or give someone new a chance to try it. I don't think either depends on everyone regularly taking a turn though.