Well you've got two of the best writers in this fandom as betas (yeah, I said it), so I'd imagine that definitely "ups your game". Obviously not all writers make good betas, and not all betas are "great writers". (I'm speaking of myself in this instance.) That's true in any field of course. (I have second-hand experience in this via my sweetie's four years in art school.) In fact quite a large percentage of visual artists in the US turn to teaching because they can't make their primary living from art, no matter how good they are. Some of them are great teachers - and some need to get their heads out of their big fat egos.

The old saying "Those who can, do; those who can't, teach" is utter bullshit IMO. Those who can, teach; those who can't, criticize teachers.