NFT Marketplace including database for storing data?

Question

I've heard of the concept of storing info "on the chain" when developing nft marketplaces(). I currently am using Javascript And Golang. When the user logs in (ex. metamask) it will save information such as the user wallet address on the backend (database). Also when users create an nft / buy one, the information is stored in the backend, to query them when sorting by popularity or such . I couldn't find any issues online resolving my issue, its not a matter of "opinions". Would this be sane? Would it brake the point of decentralized marketplaces? I found most NFT websites using GRAPHQL to communicate to the backend but im not sure what they do afterwards. Any articles? any information? should i use a database/are they better ways?