No one in their right mind thinks Herbert is anywhere close to Mahomes
What @Blessings is trying to tell you is that Chiefs model of winning is not replicable. Mahomes is one of a kind. And even with him this offense had its struggles.
Now, is a WR more replaceable than a QB just because of scarcity? Yeah.
If you want to look at a position crash aside from RB look at the safety market. Ever since teams started playing two high a lot, you either get an elite talent like Hamilton or you just pay peanuts for safeties because theres oversupply and not enough demand. A lot of vets can play the two high look.
All facts
The closest would be Lamar, and Allen(this season without Diggs).
Everyone else who's a legit SB contender will have a high-priced WR (Lamb, Chase)