A place where I won’t lose them, along with things like even MRI images (ideally)
Hm. Well… I wouldn’t call this a self-research question, it’s just a file storage question?
Generally speaking, I’d recommend a standard user-friendly file storage & access management solution like Google Drive, which offers up to 15GB free.
If you’re a techie and want to have guaranteed privacy via end-to-end encryption, I’d recommend Keybase filesystem (kbfs). (Caveat: my spouse works for Keybase.) This is up to 250GB free, but it’s also provided by a “start up” (i.e. less guarantee it’ll still be around in 10+ years).
The answer used to be MS HealthVault but even that shut down. There isn’t a turnkey place for collecting this data anymore. Google Health exited at least 10 years ago, and if Google and MS can’t do it, I don’t know who can.
I guess I see those as retrieval/aggregation solutions, beyond mere storage. But maybe that’s what the question was about.
I wouldn’t be surprised there’s other things to try for that, but – agree with your takeaway – since we’ve seen Google & Microsoft gave up, it seems to be a Hard Problem.