This was similar to Joe Montana/Steve Young, Brett Favre/Aaron Rodgers, Jordan Love/Aaron Rodgers. Even though Tom is the GOAT, so is father time. However, Bill was seriously off his rocker after the 2013 season thinking Tom was "falling off the cliff" and needed to be convinced then not to trade him. Tom had two rookies starting on the outside (who flamed out of the league), Edelman and Amendola taking over for Welker and only Gronk because Hernandez got arrested. Pats had Emmanuel Sanders signed to an offer sheet, but the Steelers being the assholes they are, only matched it at the 11th hour to mess with the Pats.
Drafting Jimmy G in 2014 was an idiotic use of draft capital, much like it was in 2008 when Bill used a 3rd rounder on Kevin O'Connell when your QB just put up historic numbers.
With that said, the Pats wouldn't have done much with Tom between 2020-2022. Probably 9-10 win seasons, but a quick playoff exit.