Open site, use the search box on the top right to look for merely the keyword "blockchain", find 1 hit which says: > We are not making "the" blockchain, and we

Open site, use the search box on the top right to look for merely the keyword "blockchain", find 1 hit which says: > We are not making "the" blockchain, and we do not claim to support decentralisation. This does not use a blockchain in the bitcoin/ethereum/... sense of the word. Perhaps in a "git" sense of the word, but I don't think that's what OP meant when asking for legitimate uses.