I don’t think you’ve read your own source right. As far as I can tell that doesn’t say paper is preferred anywhere. That document seems to just be saying, “if you use paper, use this, if digital, use this” for each type of data you want to store.

And while I agree they’re not recommending to shred all their paper documents and scan them into PDF, they’re also not recommending to print off all your electronic documents and put them into filing cabinets either. Both are acceptable formats for different things, in their opinion.

And while I agree that low acid paper isn’t likely to break down over 1000 years if left alone, the odds of the building they are in burning down or getting a silverfish infestation is actually pretty decent over a 1000yr period, so I don’t think the odds of them surviving is nearly as good as you think.

And also, while I agree that PDF will likely be replaced a few dozen times in the next millennium, it’s also really just a glorified markdown format. Every new standard will have converters to move from the previous standard to the new. Is that work? Certainly. Is it more work than actively maintaining physical archives? No. Especially since, as PDF is the defacto standard for electronic documents for every world government, any major shift in that standard will have well support paths forward for upgrading.

And most importantly, none of your points actually addressed my core point, which was, regardless of which one is “easier” to maintain, it’s clear and obvious which one is cheaper. The cost associated with maintaining large physical archives is astronomical. Buying up some cloud storage is minimal.