I have tons of PC games I "own" but can't play anymore. One of my favorite tycoon games was Sid Meier's Railroads, but it can't run stable on any machine with more than 4GB of RAM. Sure I could spin up a Windows XP VM but that's not a reasonable solution in any way. Same thing with Full Spectrum Warrior, just doesn't run on modern OSes. I can play Unreal Tournament 2003 or older Call of Duty games or... if I can find someone to play with, playing the maps and modes I want to play. I also have more than a handful of online and MMO games that I "own" but can't play because the servers are shut off.
The days of owning a game and playing it forever are so far gone that there are adults graduating college who don't remember a time when you could expect to own a game and play it forever.
PC gaming has always had an element of troubleshooting and workarounds to get them working on some systems. I play lot's of old games, and it's rare if ever that I can't find patches or workarounds to get them working.
It's also not quite the same to compare something you definitely could get working with more effort (like spinning up an XP VM) to something where there is literally no way at all, like when OnLive went away.
I'm still playing some MMO-games that had their servers shut down thanks to people developing emulated servers and recreating the game world. Asherons Call is one, Planetside 1 another. I know similar efforts exists in a lot of MMO's.
Have you tried gog.com? They support the games they sell, and often patch them so they can work on newer versions of windows (or if old enough, provide a custom dosbox launcher).
They do sell Sid Meier's Railroads ($9.99), and if you check the support forum it may be obvious if they've fixed this problem.
Having to buy it twice isn't optimal, but you get bug fixes and a DRM free installer you can download and keep and manuals in PDF form which beats trying to keep old floppies or CDs in good condition. I've bought quite a few old games I had from them for just that reason.
GOG is excellent for this reason and my experience playing older/unsupported games from them is top-notch. It stings to buy an older game again, but they're almost always inexpensive, and you can say, "Well, this is the very last time I'm going to purchase HoMM3" (or your game of choice).
They also do fine as a purchase platform for modern games, but it's less than perfect because modern games are supported and some smaller publishers choose not to push updates to their offerings on GOG.
My Steam account has 282 game going back 15 years. I'm sure there's a few that don't work anymore, but I've never come across one. PC has a great compatibility track record even if a few games from the early 2000's don't work.
I recently reinstalled Assasins Creed 2, and discovered that it was unable to load levels or start a new game.
I haven't tried hard to get it to work (i.e. completely wiping my local data, maybe just having a corrupt savegame would also cause new games to fail to load?)
If "doesn't run on newer systems" is your criteria, those days never existed (and any point in time is probably the one with the most options to run past games, due to emulation/compatibility fixes improving). Games relying on servers are a newer issue though indeed.
In general, there are almost always easy to follow guides online that take 30mins or less for getting older PC games to work on modern systems. If you care, you can get it working. This only changed relatively recently, and only because producers knew they could count on people being too lazy to take the minimum effort necessary when they can just buy a new game on steam.
The days of owning a game and playing it forever are so far gone that there are adults graduating college who don't remember a time when you could expect to own a game and play it forever.