I made the observation just a day or two ago to a friend, that when I decided I would invest in a lot of storage, I also had to invest in even more to be able to do backups...and then to perform those backups I have to be able to sync the data effectively, which has some natural scaling limits and introduces ergonomic concerns. After a certain point I threw up my hands and said, "okay, I guess the amount of data I can reasonably keep track of is roughly the amount I can keep synced across multiple devices". So, for the consumer equipment I am using regularly, a few terabytes at most.

And that solves the problem in the sense of "I have some form of redundancy", but not "I am confident that it's durable", and definitely not "I am actually curating the data at archival quality".

But when I investigated using PAR2 I had another thought, which is that, in a sense, this is a quality-of-service type of issue, and those are always subject to variable standards. And part of my problem is like what you allude to - I can't easily specify how important the data is. If only I could just say, "I only somewhat care about these commercial multi-gigabyte sample libraries, but I care deeply about my password database, so please do the right thing with each." And that's something that - whether it's surfaced to the app or to the user - it really needs a much greater degree of coordination to pull off. As it is, there's a lot of redundant guesswork taking place.