What standard of proof are you willing to accept?
Both the primary and secondary market were very active with distinct identities. The primary market (buying collections directly from a new issuer) is still okay right now. The issuers are still making a lot of money.
The secondary market’s “floor price” concept is manipulated by the crowd, as with all collections outside of the NFT space as most individual pieces never got a bid to begin with. You hear one piece sold and you try to sell yours at the same price, so does everyone else.