Many people wanted to see privacy tech implemented in Bitcoin's base layer, Monero people included. Liquid was presented as an alternative: "we don't need privacy on the base layer and we sure as shit don't need Monero, we can have privacy in our federated sidechain instead." It's another Bitcoin maxi product built for Bitcoin maxis who want to avoid Monero. As a result, by pushing privacy out to a separate layer, code quality suffered and the protocol got hacked. Liquid is absolutely relevant to Monero. It's ignoring history to assume it isn't.