I don't believe Burnham is a Mary Sue I really don't like that phrase at all and it was used a lot by people I do not wish to be associated with to be honestI’m talking about a specific group of haters who have hated the show from the beginning and don’t see the evolution or changes the show has made. Criticism is great; continual, completely biased commentary is what gets tiresome.
I’m also a little confused why you argued against the Mary Sue peddler stereotype and then go on to make a Mary Sue argument later in your post anyway? Can’t have it both ways IMO.
I’ll also address the actual Mary Sue argument. Some haters dislike the show so much that they can’t see (or maybe aren’t willing to see) examples of growth in its writing and portrayal of other characters. I mean last season we had Pike save the day multiple times. Airiam sacrificed herself to save the day, with Nhan helping while Burnham was actually emotionally unable to do so. Stamets made the key repair to power the ship hours after recovering from a severe impalement. Saru defused the situation on the mining planet, then figured out how to get his crew’s morale back up. Culber is getting some pretty good screen time lately. Are these all not examples of giving other characters their “scraps of glory?”
This is not much different from traditional Trek where each character often had the chance to contribute something, but the main characters got most of the glory. The only significant difference is that the seasons are shorter so you have less flexibility to dedicate whole episodes to supporting characters. And even then it took 4 to 5 seasons to flesh out characters like Geordi or Bashir.
But the writers do take unnecessary steps to get Burnham front and centre and I don't think it works. Now you have said the show has changed and it has bit it would work better for me if that aspect changed more and I think it a fair criticism