This is depressing. I cannot stress enough how critical emulators are in this area. Especially emulators that can emulate old obscure CPU architecture or whatever else needed to run super old games. We can preserve them forever this way regardless of available hardware. Keep ROMs archived on many places too, cold storages, etc.
This is one of my favorite GDC talks and it's about this subject with a sizeable segment devoted to the second paragraph in this article comparing Video Games to the availability of classic Movies.
I can't actually open the URL but I imagine they are speaking about alder generations and arcade cabinets. I recall a GDC talk about piracy where they discuss attempting to find any information on some of the earliest releases for a studio and finding one or two adverts only,