Neither Brady nor Manning would have done what they've done behind poor protection.
Prescott needs to play like Mahomes and Allen. The pocket could be a trap for him with this OL.
Those guys create their own protection by being 1 step ahead of the defense every snap. Yes, they'll do better with a strong OL, but they're never going to do horrible no matter how poor their OL is.
Colts 2010 (Peyton): 16 sacks
Colts 2011 (Other QBs): 35 sacks
Denver 2011 (Other QBs): 42 sacks
Denver 2012 (Peyton): 21 sacks
New England 2019 (Brady): 28 sacks
New England 2020 (Other QBs): 37 sacks
Tampa Bay 2019 (Other QBs): 47 Sacks
Tampa Bay 2020 (Brady): 22 sacks
Seems highly unlikely that the Colts and Patriots got significantly worse on the OL the moment Brady and Manning left AND at the same time the Broncos and Bucs got significantly better on the OL the moment Brady and Manning arrived.
They prevented a lot of sacks by being all-time greats. That's why they're Brady and Manning.