Personally, I don't care for baseball cards, I value them about as much as the paper they're printed on. But collectors like them, so if I found one (I dunno, dropped in its sleeve into a tip jar?), I'd check if someone else wanted to pay for it before I started using it as a bookmark.
Same deal with NFTs. The difference is they're brand-new and white-hot, and it remains to be seen if they have enduring value.
My guess: NFTs will continue to be valued, but the vast majority of those which exist right now (and of every NFT ever minted) will be worth so little that it isn't worth the transaction fee to transfer ownership.
The John Cleese Brooklyn Bridge though? It's a great joke! Might not be worth whatever it goes for down the road, but it will probably still be worth something.