What's the most annoying experience you had with NFT or NFT-marketplaces

Hi, we are a small startup that just launched an NFT marketplace for YouTube videos (I'd rather not mention its name here so not to seem like a blatant PR)

NFT space is really early and I know there's a lot of work to be done. Or there might be just too many problems so we're lost where to begin with!

Could you share your experiences with NFTs, other marketplaces(e.g. opensea, nifty gateway etc) or other crypto-related things(e.g. metamask) so we can plan ourselves where to focus on?

Thanks in advance! People here at HN rock :)

PS: We know gas fees & txn lags suck, so something other than these two please!