I think we are starting to see what those huge QB contracts can do to teams. It is very hard to build deep complete teams when 15% of your cap is going to your QB. Next year, 70% of the Chiefs cap is going to like 6 players (it isn't as pronounced this year, but you can't sign a bunch of guys to 1 year contracts either).
That may very well be Tom Brady's greatest skill. Not only taking less money for himself, but getting other players to sign for depressed value contracts as well allowing for deeper more complete teams. The Bucs this year only have 4 players at more than 4.5% of the cap and Godwin's franchise player cap hit of 8.78% is the most on the team. That is part of the reason the Bucs have been able to be so good and with such a complete team. Brady's cap hit is only 10.545 million (5.79%), which jumps to only 16.9 m (8.05%) next year, before hitting 24 million in 2023 (that one they will renegotiate).