I think what the league has to figure out moving foward is QB contracts. The current mechanism is flawed, it rewards below average to mediocre qbs. Lately, we've seen too many of them (Flacco, Goff, Wentz, Cousins, ...) and they really cause too much damage. I don't know if teams choose riskier approaches in regard to roster structure and it seems like there are more all-in teams than ever.
I don't think the league needs to do anything. It should be on the teams. If they don't want to play high $ to average QBs, then don't do it. They're not forced into doing anything.
It's a double-edged sword that can't be solved. Nobody saw the decline of Carson Wentz coming, and if the Eagles move on from him, and he ends up on a team with a competent Oline and some actual receivers, he's going to decimate other teams and make the whole league look bad for doubting him.
Jared Goff pretty much checked every box of what you wanted for a franchise QB when they handed him his extension. 11-4 in 2017, 13-3 in 2018, and a SB appearance. Strong statistical numbers in both years. He checked the box as a statistical quality player, and as a winning player.
Cousins was a stat compiler, much in the vein of a Stafford, Ryan, etc.
Basically it comes down to this... the ONLY franchise QBs who are living up to their 2nd contracts are guys who a) put up quality statistics and b) win a lot of football games. And realistically, there's less than 10 of those guys in the whole league.
As pretty much every team in the league as figured out, it'll take you multiple iterations of high draft picks and talent development to find somebody who does both. And when you do, sometimes even then, you get a Jared Goff.
You can pay the stat guy a lot of money, and he may never win anything (Stafford, Cousins). You can also pay the guy who wins a lot but isn't stat-heavy a lot (Flacco), but when the winning stops, all you have is a guy who isn't very good.
There's nothing the league can do to stop that. Putting in some special QB "salary cap" adjustment only favors teams that suck at evaluating QB talent. NFL teams are the problem, and its up to them to correct the mistakes.