Drag can archive it locally just fine. Is it worth storing hundreds of thousands of messages & attachments that price out self-hosting & low-spec hosters & medium-sized communities on a budget? These storage costs add up quickly & without lots of nodes, the network is no longer federated but held by a few mega hosts like Matrix.org & a sprinkling of single-user hosts. I have seen many servers shut down due to costs. This tradeoff just isn’t worth it for a triving, decentralized platform (Mastodon suffers similar duplication issues).