I think major clients should have their own proper local databases.

It would greatly enhance the user experience, smooth feed and more reliability.

This would also reduce internet and battery usage, as notes and other stuff wouldn't need to be fetched every time also resulting in a smooth feed.

A local database is also the best personal realtime backup anyone can have. It can also keep your relay data up-to-date.

Good Local Database can improve all these things without any external server!