OK, so you're now hosting the post-support servers for Anime CCG Pocket Collection 2045, the briefly popular collectible monster card game.
Where do I make an account? Does my old account work? Did you get all my personal info along with the game code to make that happen? Where are you storing my passwords? How are you linking my account to the first party account I used to buy the game? Who do I send a letter to exercise my access rights according to GDPR? In fact, are you GDPR-compliant? How do you know? How do I know? Who is running moderation on the chat? Are bans issued and enforced? Who is to blame if there are legal ramifications from something related to moderation? If I want to buy a skin for the game's popular Electric Squirrel mascot and my transaction doesn't work, where do I get a refund? If you don't handle MTX in your private server, then who makes the code changes to allow players to just buy everything without MTX or to not allow things to be bought? I mean, the entire game is built on collecting Monster Cards, so if everybody has everything it's gonna get weird. Are you rebalancing the game as part of this process or nah? Hey, there is no seasonal content in the game and it feels broken. Can you re-run some old seasons? Who decides which ones? Do you even have the right content server data for that? Where are you storing my inventory and the data for my Electric Squirrel Home Building feature? Are you paying for the server costs of doing that? What happens to my data if you run out of money the way the original developer did? Hey, I also want to run a server, but the entire thing is supposed to matchmake globally and cross-platform, so who says you're the official host of the game now? Why can't I run it instead?
Dedicated servers are more or less trivial, it's not about having a rack of 5090s. Plenty of games with small servers rent those out or let people self-host them, from Minecraft to Conan.
The problem is running a service.
That's why this is so hard. Multiplayer games revolving around standalone matches are whatever, but modern GaaS stuff is... fundamentally not that. Running the game and making the game are not that different from each other, and running the game gets expensive. As in, making-the-game expensive.
We need a solution so that enterprising communities can at least try to work around all those issues without getting immediately shot down by IP holders, and we need a solution to preserve this type of fleeting, fungible media in some form. I just don't know what that is, and I'm pretty sure it's not a one-size-fits-all thing that maintains the game you paid for running as if the servers hadn't been taken down. I just don't see how you set that up as a general rule that everybody can just comply with.
EDIT: Oh, holy crap, I could have saved myself the fantasy scenario. Turns out Faliszek went ahead and broke down exactly what it took to do this for their game. Because they did do it, despite him being actively hostile to this initiative.
I'm gonna pat myself in the back a bit for having caught a lot of the actual pitfalls he describes, but I still recommend giving it a watch. It's not an angry video, it's super informative and well worth the time.