Your argument is sound but your examples are flaw. Take Chelsea as example, they have 4 strikers, Giroud is only their 4th choice although most reliable. They have Werner, Abraham, and even Havertz. You don't spend 100m to replace your 4th choice striker, you spend 100m only if you are convinced that your 1st to 3rd choice are not good enough, prepared to bite the bullet and correct your expensive mistake, which is likely but not the way that you present it.
Take PSG as example, their top strikers are Neymar and Mbappe. If someone give them a 100m for Mbappe then perhaps they will spend the sum on Haaland.
But yes, City, RM, Barca, BM are all desperate for world class striker. If you take away the cash strapped clubs, you still have City, BM, Chelsea in the market