You're arguing a strawman here, and responding with emotion to the question of "are dedicated servers for old games expensive to keep running?". I'm going to skip the rant about single player games and queues.
> No,they are not. Especially since op mentioned most popular games having ~10k concurrent users.
> The added costs are studios running MMOs, and those aren't insane either. People hosted their own servers since the beginning of the net.
Do you know how much it costs to run an online game?
Assuming we're not talking about MMOs (because you're the one who said the added costs are studios for MMOs), a game with 10k peak concurrent users, and 10 players per session will need 1k concurrent sessions. Assuming the server needs ~ 2 cores and 4GB ram, you'll need 2000 cores and 4000GB/4TB RAM. We're talking "old games" here, so I think it's reasonable to assume that we're not running autoscaling containers, and frankly it's probably a bit of a stretch to assume that there's anything other than a fixed set of servers if we're talking games from the 2005-2012 era.
Hiring a 32 core/128GB Server is ~$1000/month from OVH, so to keep the peak capacity for the game available, you're talking ~$60k/month, plus various online services (login, auth, party, matchmaking, etc), licenses for things like SQL server, windows (yes, windows is commonly used in game development even up until recently). That's assuming no maintenance, or development costs happen. You have to budget for handling things like log4j, keeping CI/CD pipelines up to date to keep SSL certs valid and rotated, handling player support for those games, etc.
That's not nothing, and while it might be manageable for EA/Ubisoft for your game, what about the other 10 games they have with 10k players each?
The added costs are studios running MMOs, and those aren't insane either. People hosted their own servers since the beginning of the net.
The odd runaway hit MMO shells out more but also makes a ton more. Even then we see companies cheap out and make us sit through server queues.
Live services these days amount to little more than checking license to play, loot-boxes, battlepass, etc.
And yet because of those evil cash-grabs I can only play the game a few years even for single player games.
Live services have become a worse dlc, as we knew it would in tge beginning.