Having a better O-Line and receivers who can come out of the break means Mac would have more time to make decisions and wouldn't be rushing throws and making bad passes.
One of Brady's keys to success was having an O-Line that could hold long enough for him to throw and receivers that could get separation so he could fit the ball in a tight window.
How anyone can't see that is beyond me.
Brady got rid of the ball faster than any QB in history.
Brady was one of, actually the biggest, key, to the success of the O-Lines that protected him.
That said. Mac was unpressured when he lobbed that putrid ball off his back foot at a wide open TE. Wide open. The receiver got open, and the O-Line did it's job there. They still suck as a line overall, but Mac's decision making is trash.
I'm sure him getting killed half the time has played it's role, but the fact remains that he consistently makes terrible decisions, even when he has plenty of time.