I don't think Fields is by any means lighting the world on fire, but over his last 6 games this is what we're looking at
QB Rating
Lions 88.3
Vikings 87.3
Lions 105.2
Vikings 36.7
Commanders 125.3
Broncos 132.7
Over that time he is 10TD/2INT
He's had 1 terrible game, 2 adequate games, 1 good game and 2 great games. It's not good enough to no question want him back, but it's also not bad enough to want him gone regardless. It's solid performance that likely puts him in the upper half of NFL QBs.