It's both, as I said in the other thread, Burnham is a complete fail as a character, she's a gimmick that doesn't work because of the very nature of the show and on top of that is hilariously poorly written (like Discovery in general) which just leads her to becoming basically an overpowered Mary Sue.
She's a human raised on Vulcan which explains why she's awesome at literally everything because, Vulcans are smarter and stronger than humans and Burnham was the highest ranked ever graduate out of the Vulcan science academy, so she's better than even all the Vulcans ever, but the writers would "balance" this (if they ever could) with the fact she's basically a Human pretending to be a Vulcan so she doesn't have good impulse control because humans are naturally emotional (Just ignore that Vulcans have far stronger natural emotions than humans and it's their training that allows them to suppress emotion but whatever) and this is what would cripple her along with being unable to connect with any other crew member. But even with this, okay if she's a secondary character in an ensemble whatever.
The problem is then they built a Drama TV show around this single character who is supposed to be the complete emotional crutch of the thing and Discovery isn't just Drama, it's like soap opera level melodrama at 110% always so Burnham is never an unemotional, purely logical Vulcan in this show, she's just another extremely melodramatic human like the rest of the cast, except as well she's overpowered to just absurd levels because essentially "Half-Vulcan" which allows her to be impulsive unlike a Vulcan and be super awesome hence why Burnham constantly pulls off insanely impossible shit like that eye rolling asteroid field sequence and basically solves literally every single thing on the show, even when other characters do "solve" something, it's Burnham that spells it out to them in the first place.
Another thing is, SMG just can't act as a Vulcan for shit, her "Vulcan" mode is to just do a stupid strained face like she's constipated and then talking with the intonation of a voice over in a movie trailer in this weird whispery voice which no Vulcan talks like ever. She overacts in this weird goofy way everywhere. I have no idea why people think she's a good actress, she was terrible in The Walking Dead and terrible here.