PCs didn't become mainstream until well into this century, and didn't become a common part of society until around 10 years ago.
Uhm... what?
I'm sure it depends on where you're living and all that, but even little old grandmas were stuck learning how to use PCs by the middle of the 1990's in the United States (to use this newfangled "email" thing). Ten years ago was actually past the point where PCs were getting displaced *out* of home/recreational use by appliances like smartphones.
and despite Windows taking off, the use of DOS and similar systems was still massive and the future of PCs undecided by 1995.
Not really? Sure, people were still using plenty of DOS programs in 1995, but they were inevitably running them on PCs with Windows of some form preinstalled, and it was
game over when Windows 95 showed up. If you worked in a law office or something in 1996 you might still be plugging away at WordPerfect 5.1 in a DOS full-screen session because you have literally thousands of documents in that format (and that was still the standard if you logged into Pacer with your modem and downloaded something from the court), but you had Windows 95 lurking in the background, and it was only a matter of time before you found yourself also having to deal with Microsoft Word docs sneaking onto your docket.
I mean, believe me, I'm saying this grudgingly. There was a lot of hype and optimism in the early-mid-90's about these amazing "new" technologies like RISC CPUs that were going to spawn a completely new generation of PCs (with better operating systems to match) and how Microsoft and Intel had no hope of stemming this incoming tital wave of competition, but... no, it didn't happen. And ironically we can probably drop a hunk of the blame for this on
MS-DOS; at this point they had held an absolute stranglehold on the PC market for nearly a decade and even though, yes, the requirements for a new PC had changed from a machine with a couple floppy disks and a CGA card to hundred-plus-mhz CPUs and megapixel color displays between 1985 and 1995 what
hadn't changed was the customer expectation that when they walked home from the store with this
new computer they'd be able to grab the installation disks for whatever
old software they had that they wanted to keep, install it, and keep on running it for as long as they wanted to. Every company that actually put an "all new" machine out in the 1990's failed hard and fast; not that there were many that even really went on sale, most of these ideas ended up stuck in development hell
(See: Taligent) and only eventually emerged as bits and pieces of tech welded onto other existing operating systems.
(Apple was the only company that managed to survive switching CPU platforms, and they were only able to pull it off because they A: had such tight control of their platform, B: had (luckily) designed their base OS to be so hardware agnostic, and C: the CPU they switched to was so much more powerful than the CPUs Motorola had essentially abandoned development of around 1990 that customers didn't perceive their new computer as being slower than their old one when running old software, which was the case with any RISC computer that tried emulating DOS software. The hype around RISC CPUs was 100% dependant on the assumption that Intel wouldn't be able to apply enough in the way of go-fast hardware techniques to their CPUs to keep up (or even stay within an order of magnitude) with the performance of new designs; that assumption was already questionable when the Pentium came out, and was pretty much kaput by the end of the 1990's no matter what Apple bravely tried to pretend into the early 2000's with their rigged Photoshop benchmarks.)
Again, man, I dunno. Maybe if your memories of the 1990's are from a less developed/third world market where various 8-bit computer cast-offs managed to hold on longer because of local economic conditions your perception of just how dominant MS-DOS/PC Compatibilty was by the turn of the 1990's might be a little clouded. But at the global level the writing was thoroughly engraved on the wall well before 1995, whether you wanted that future or not.
That DOS survives until today is remarkable, and mainly it's only DOS data structures that remain.
And that proves the whole point; the "PC Compatible" became so embedded in the very DNA of the computer industry bits of it still linger to this day. I mean, sure, you could actually more broadly argue that applies to CP/M, since some of the concepts that modern OSes use (IE, the separation of roles between BIOS and OS level APIs, etc) were embodied in CP/M and MS-DOS started as a broadly CP/M-compatible workalike, but if you play that game then you're perfectly free to just keep notching that bar down to the DEC PDP-8 OSes that CP/M freely borrowed from, and from there to various research OSes dating back to the early 1950's... etc. The thing about MS-DOS' DNA is the majority of computers sold up to this very day can
natively run an MS-DOS binary without CPU emulation. There has yet to be a clean break with a computer architecture first sold at retail in 1981.
CP/M was certainly an important and influential operating system of its time, but that time was between 1974 and the very early 1980's. The modern paradigm of a completely binary-compatible-across-hardware-vendors "universal" computing platform didn't happen en-mass until the PC Compatible, and it's kind of interesting that it was a thing that was arrived at almost accidentally. If history had gone just a little differently MS-DOS could have ended up like CP/M, a core OS that ran on a bunch of mutually incompatible (in terms of disk formats, graphics hardware, etc) business computers that might have all found their own little niches but never actually gave the home customer what they really wanted. In *that* world, sure, maybe we all would have migrated to something all new in 1995. But in our world, nope; the organically spawned PC compatible, with all its ugly warts and goofy idiosyncracies, was forced to keep on evolving.