The problem isn't the franchise QBs. It's the less than true franchise guys who get paid like they are, and who raise the paydays for the truly great ones. Eli Manning? Puhleaze. He's somebody the Giants should have been trying to replace with a young QB - and once they found a guy they liked, jettison Eli and use the savings to have multiple good players elsewhere. Meanwhile, the great QBs look at the money Eli got and deservedly want more. (note - I'm not saying Eli has had a crap career. It's just that without a great team around him for two Super Bowls nobody would mistake him for anything but a good QB who can be replaced.)
Actually I think the problem IS with franchise QBs.
The Packers and Rams the last two years is a fascinating example to use. Rodgers got hurt in 2017 and the season was completely, 100% over - the Eagles showed the opposite, and this year the Rams are set up to overcome that as well. Say what you want to about Bortles - he played well enough to make the Super Bowl and our team is better than the one he did that with.
Here are the tiers we have had since QBs started making stupid money:
Patriots - exception to everything for numerous reasons including their division, but it's worth noting that Brady has rarely been a top paid QB in his career and they've sustained success
Packers/Saints/Colts and Broncos (with Peyton) - these are the cream of the crop QB-wise since QB contracts exploded - only Peyton has won Super Bowls while being paid that kind of money, and one of the Super Bowls that he won he was one of the worst players on the field - that's not really relevant to his contract though, but it does illustrate how a TEAM, not a QB, wins the Super Bowl. The Saints, Packers and Colts always seem to make the playoffs and almost always lost to a better TEAM.
These are the elite of the elite in NFL history - and they have a combined 4 Super Bowls. Brees and Rodgers can't even get back to the big game, and check out their contracts the year that they each won the Super Bowl.
But paying just "franchise" QBs? Horrible mistake. These guys are paid exactly like the guys above - but are worse players. Wilson, your Eli example, Matt Ryan, Rivers - these guys are all franchise guys and have been borderline elite in one or two years of their careers, but they are not on the same level as Brees/Brady/Rodgers.
If I were Seattle I would look Russell Wilson in the eye and say "we're not paying you as much as Brees or Rodgers because you are not as good as them".