True...it doesn't put the Patriots in cap hell. It's the cost of doing business with a non-rookie QB contract.
I am 1000% in favor of bringing Brady back any price, and I think people are not seeing the forest here and are staring at the trees and taking for granted the historical rarity of being a fan right now even at the end of the dynasty; at the same time, there's a reason for some healthy skepticism on bringing back Brady at that price from a short-term competitive standpoint. The problem is the lack of young assets on rookie deals due to some dreadfully poor draft returns for years. This will catch up to every team, though if you had a rookie (like Stidham) and he was good, you could neutralize a lot of the negative impact of these drafts. But assuming they bring back Brady, they'll have maybe $15-20M, maybe some restructures and cuts to bring up that number to $25-30M.
But that is also without accounting for McCourty, Thuney, and Van Noy, among others. So it's hard to imagine a much greater overall net impact when they would presumably just be trading some positions (defense especially) for some skill players. There just isn't a ton of cap space to work with considering all of the holes on the roster. So unless the team can really defy the odds here, it's likely trading one set of problems for some others. The handicap of like five bust drafts in a row, and paying a reasonable amount for a QB, is typically a recipe for failure.