How OpenSea/Rarible/Blur/Nft Marketplace works without proceeds?

[NickoMenty]

I tried to find discussions on this topic, but either I don't search good enough or no one asked.

Can't we just use openzeplin guardian to sellNFTs and send money?
Or how do other nft maketplaces do that?

I am really interested in it, if somebody could tell, I would be glad <3