Farcaster

farcaster clients should locally replicate all of the logged in user's messages and sync it to icloud so that if they don't pay for storage and their data gets pruned the app can just prompt them to pay and republish all their data from the backup

I agree that there should be some kind of solution to the question of, “where to store user messages beyond the blockchain limit”, but is iCloud (or any privately-owned cloud service) the best long term solution?

To me, it feels like it ideologically runs against the principle of ownership of data that decentralised apps represent.

Right. The way that farcaster works is that you rent storage on the network and if your storage expires your data gets pruned from the network

I’m essentially proposing that the client e.g. warpcast automatically backs your data up to iCloud (which is free) so that if your storage on the network expires and you come back, you can easily restore your data