There are ups and downs to that approach: If we're hoping for a solution that works for the average person, e2e encrypted solutions often lead to people who do not fully understand the risk of losing their keys to lose all of their data. Even without e2e, you'd be surprised how many people I've personally interacted with who have gotten permanently locked out of a Gmail account and unable to convince Google to give them access again.

One idea I think is really neat though is decentralized backup solutions, where an e2e scheme would work really well: Your home server could have a key to store encrypted versions on someone else's server (and vice versa for theirs). Losing a key would still be problematic, but only in the case you also have lost your primary server.

That would be a good idea for file sync and documents, but wouldn't be as effective for RSS readers where the server needs to know the list of URLs to fetch, and terminate the TLS connections itself (unless the client does the fetching and pushes up articles in an encrypted format).