as for this question, that is a different issue. i more or less said it is what it is, and the way the league is structured now the qb has a disproportionate amount of leverage. how i think it could or should be changed would be an entirely different question, well beyond the scope of this thread, and it would probably give me and everyone else a popsicle headache.
as far as your mahomes point, i already acknowledged his number will go up. so if he goes from 45 to 58, that would still leave goff at 92% of mahomes, when he is nowhere near 92% of the QB, even though his relative QB rating says he is. goff will still be nearly the same as burrow, when there is not a massive time difference. the payroll curve between QB 1-10 is alot flatter than the talent curve between 1-10, in my view. the qbs just have alot of leverage, and they use it. running backs and safeties are in the opposite boat. heck you can get mostert, who put up some of the best numbers in the NFL, for almost nothing!