It may be helpful. Consider online backups for your important digital documents

[cdmackay]

(09-08-2019 11:47 PM)Albert Chan Wrote:  I rather keep physical documents, if possible.

Even if the data is digitally stored, and in good condition, we may be unable to read them later.

Digital Preservation and the Doomsday Project

Quote:Less then 15 years later, it’s system was unusable. Compare that expensive failure to the longevity of the Domesday Book:
a record written on paper in Latin in the 11th century and is still readable today.

That's a cautionary tale (as is Bill's!), but I think keeping multiple PDF copies, both at home and in various clouds, updated/checked yearly, is going to last as long as is required.

Given the huge amount of documentation worldwide in PDF, it seems reasonable to expect readers/converters to remain available for decades. And as soon as its end is in sight, converting to whatever comes next shouldn't be hard.