Didn’t it take a season or 2 for Romo to get the commentary right? He had play predictions down pat but was still lacking iirc
I think the difference is that Romo was replacing Nantz, who was never all that great to start, and had clearly reached the point where it was time for him to go. Even though he wasn't perfect to start, he as an upgrade.
Brady forced out Greg Olsen, who was perfectly fine, and hasn't appeared to be an upgrade in any way at all so far.