They recently introduced a new format that has, in my opinion, fixed a LOT of the issues that have built up over the years. All cards are now legal (yes, even Pot of Greed) but they have a point cost; decks can only be 100 points. The most broken cards cost all 100 points.
It’s brought a lot of balance to a game that suffered hard from power creep and rules creep.









Mariner in Lower Decks is far more immature and makes far more questionable choices, but she is a beloved character. I think Burnham’s issue is that she has the emotional stability of a high schooler. You can have immature characters, you can have characters that disrespect the chain of command, you can have characters who make lots of mistakes; but you can not have characters who have a mental health crisis every other week.
Discovery is like a Star Trek show if nearly every character was some version of Lt. Barclay; crippled by their own insecurities and forced to overcome them again and again without ever seeming to actually grow out of them.