Luisfius: At least in my region, PC games were not particularly viable.
Not in my region either if we're talking about boxed PC games, unless you were happy getting PC games on burnt blank discs with the game title sharpie'd on with very obvious typos, packaged in like those cheap plastic or paper wraps, and if anything, I got like around 5 boxed authentic PC games. But...
(the rest of this post expands on my earlier one)
Your region may have been screwed when it came to acquiring games as does mine, but the PC platform itself was never at any point unviable for anything devs or its users wanted to do with it. Doom never needed Steam to launch, yet it and its sequel Doom II are still beloved games to this day, and to this day Doom source port developers get into all sorts of drama, for a game released in the 90s (see how UZDoom started). Before Skyrim did the Steam-code switcheroo responsible for Steam's rise, the Elder Scrolls series and more so Morrowind and Oblivion were basically a modder's haven, and they still are today. At this point I'm just echoing AB2012's post.
Although I'll add to his post, that Minecraft has started being a thing in 2009, which would eventually go on to be the #1 best-sellin- scratch that, Tetris took its spot now, but still, it is currently #2 best-selling of all time, and even before Mojang's acquisition by Microsoft in 2014, Minecraft was a pretty hot game in its own right. All it took was one guy coding something in Java, and by that point Steam barely had any presence or impact on the platform (it was as far as I remember, no more popular than EA's Origin or Ubisoft's Uplay).
I really don't see how PC itself as a platform wasn't in a favorable position to begin with. Distribution is another story where Steam can take a tiny bit of credit, but not the general well-being of the platform.
Microfish_1: I recall my physical disc for Euro Truck Simulator 2 is...a DVD
But the jewel case for American Truck Simulator had... s a steam code. >:-(
That was one annoying reason I got steam.
Any particular billionaire in mind in your post?
Case in point. From then on, a majority of physicals were already either Steam DRM'd or didn't even come with the data on the disc. At this point if you were used to buying discs and found out you still ended up downloading the games, you'd sooner just buy directly through Steam than go to the store, open the game box, realize it's got a Steam key, redeem it on Steam, and... get to the exact same spot you could've been? Yeah. I'm not surprised.
Also this Billionaire McBillionaire would be the one with the yachts, owner of Valve.