I just explained how your design lets a payjoin sender could drain the receiver's wallet. Do some research before spreading misinformation:
"In exchange for the privacy benefit, the sender has to pay more fees than a normal transaction. It is a con for the sender, but a pro for the receiver, since the receiver does not have to consolidate its coin later." - @nopara73 (coinventor of payjoin)
You are wrong. If what you claim were actually implemented, it would create an attack vector where the sender creates a payjoin transaction at a high fee rate and burns the receiver's input.