You say that but my Villa ticket sold on the exchange within half and hour. Maybe just a question of timing?
On the other hand, my Chelsea ticket was also put on the exchange and didn’t sell ( not really surprised though at £78, plus fees on top for the buyer).
There will be exceptions but the chances of re-selling at the moment must be pretty slim , there were an awful lot of tickets up for re-sale and looks like several thousand didn't sell.