Since I’m talking about reliable long term archival of critical encrypted data here, let me again ask: in your opinion, what is the likelihood that in 50 years time, with 1Password long gone, my grand children would be able to run that local 1Password client and successfully decrypt the data?

Because I feel pretty confident that gpg will still be around (though hopefully long deprecated), that gzipped files would still be able to be opened, and everyone would still be able to open a csv file. Without any specialised software, sdk or whatnot.

If this scenario doesn’t concern you, that’s fine, 20 years ago it wouldn’t have been my concern either. But the older I’ve become, the more I think about this stuff.