The actuality of bit-rot in media is uncertain. Many documents 500 years old are readable-ish if you have the skills and accept that some parts may have decayed. That tells us a lot about te exact media people used way back then.
The trouble with digital records is this:-
Searchability is a requirement (even though we don't expect that with written records). The reason is that there is so much of it when compared with the sparse records of times past. So you need a 'good' copy for data analysis and some original media to inform historians of the future how we looked upon the information, or what 'ordinary people' or 'ordinary businesses' had at their disposal.