I wonder that too, perhaps by encrypting the data with a key generated from a long passphrase meaningful to the user, that nobody could possibly guess. Then just store the data in a permanent cloud like IPFS, pinned with 4EVERLAND, Filebase and/or Pinata:
https://docs.ipfs.tech/concepts/persistence/#pinning-service...
Maybe someone could write a provably private client-based browser decryption script, hosted on various websites. We might need a new browser spec that sandboxes pages until they're unsandboxed, allowing them no egress/ingress or even local storage or cookies.
Or better yet, take that choice away from browser vendors, and create a runtime in the browser that simply can't be observed, perhaps by using zero-knowledge proofs.
Writing this out, I wonder if the issue is due to longstanding incomplete browser architecture, going back to when the web went mainstream in the mid-1990s. Or maybe it's still just an open problem.
Solve private distributed durable storage, along with a base level of secret computation eventually running about the speed of a 6502, 286 or 68000, and we wouldn't need free services that inevitably get privatized and ensh!ttified.
I have no idea if something like this already exists, I'm just speculating as to what base functionality it might need from first principles.
Also I wonder if similar techniques could be recruited to build an OS around cryptocurrency. That way a meta economy could run alongside the corrupt economy, and shield users from currency devaluation and other wealth inequality drivers used by the ultra-wealthy to increase the value of the means of production that they own relatively, so that they can buy more.
Arguably the process of wealth concentration is so fundamental that it puts a countdown on capitalism, driving it towards the late-stage capitalism that we've had since about 1970 when productivity diverged from wages, and eventually revolution which results in socialism/communism or even permanent authoritarian dystopia like on Star Wars. In a way, it's in the best interests of the ultra-wealthy to build meta economies, which of course makes those economies suspect and probably vulnerable to exploits, especially in the AI age. We've seen how crypto has created black markets capable of capturing governments, so maybe we should be careful what we wish for.
But really I just don't want to type my password anymore.
Nit: IPFS is never a "permanent cloud", even with pinning services - you stop paying, eventually the data will be gone as no one will serve it anymore. You might be looking for Arweave for better permanence, which 4EVERLAND also supports as a storage target (although there is no way to "update" the data as well)