The publishing company often deleted it after the game shipped, thinking it just took up space.
Floppy disks were not cheap, expensive, easy to get, or reliable. It sucked.
Even on the U.S. east coast, I remember having to travel over an hour to get to the nearest store that sold floppy disks. Each BASF FlexyDisk cost $18 in 2026 money. So $50 if you wanted redundant long-term storage of one program.
That's why we printed everything out all the time; especially for archive storage.
…which also turned out to be a bad idea. Just in a different way.
I'd guess that any of these media is sketchy for long-term archival storage.
I've got probably 30 5.25 floppies in my house, and I have a 5.25 drive and an old motherboard that can probably recognize that drive, and I've got the cables to connect the drive to the motherboad (and power supply). I'd guess that there's maybe a 20% chance that, if I spent a week trying to mash it all together I'd be able to get some data off of some of these floppies.
On other magnetic media the chances are between "haha, no" (oh, you've got an old 8 inch 10mb Bernoulli disk?) to 5% (oh, a QIC150 tape).
On the other hand, if I found a stack of moldy greenbar printout of some data, I'd say that most of the data can likely be recovered, and likely for not a tremendous amount of money.
Get a Greaseweazle and that floppy drive will work on any modern computer (macOS, Windows, Linux). I've been backing up floppies from a disorganized retro PC collection I bought, and almost all of them still work.
A company of any size wasn't archiving stuff on freaking floppies. In the 70s and 80s most video games were developed on big iron—PDPs or VAXen, usually, and data from those was archived on paper or mag tape. If you were renting (or stealing) time on one of these, as "Micro-Soft" was in its very early days, then printing stuff out may have been more economical. But major game studios of the day had resources and means of bulk archival that didn't involving buying a bunch of floppies at Lechmere.
You vastly overestimate the budget and abilities of most software houses of the day.
For every Atari or Epyx, there were many dozens of very significant publishers who did their work on consumer-grade hardware.
Except for Atari and less than a handful of others with previous income, none started with PDPs on hand. They had to work up to that.
It's not like today with everything consolidated and full of VC money. Bootstrapping your way to success was de regur, and the playing field was wide open to anyone with a home computer and a little talent.