Some papers cannot be destroyed. Some papers have a predictable life longer than five to 10 years, such as patents, long-term contracts, documents showing paternity, tax basis of purchases, wills. Ramirez sets the minimum time at five years. So would an unadopted, proposed Rule of Professional Conduct. It is impractical to believe that files must be maintained forever.
Few people have the storage space.
Those that do will be confronted with the issue that some time in the future, somebody will have to make a decision about the stored writings. It can be your partners or your kids, your landlord or the janitor, but somebody has to decide. Properly, it should be an attorney, acting with the clients' interests in mind. It is proper to destroy the file after its useful life has expired. An attorney has to decide what papers cannot be released to the client.