A team can have a top 5 QB hit and be in a stage where they have a bunch of rookie deals else where that put you over the top. Or just do a really good job managing the cap in every other way.
Having a top 5 QB contract doesn’t stop you. It makes you have to be better everywhere else. And once in a while a team will overcome it.
There are no hard rules. It just makes it a little more challenging to have a top paid QB on the books. But obviously having a top QB helps too. So it’s just that balance.