And archive.org is not a replacement for a website, not even a Fandom wiki. It's horrible to use and you're lucky if it indexes a quarter of what you want, especially on a property as big as a wiki. And it's read-only.
On Fandom I can still log in and make improvements.
The issue is that Wikia/Fandom, Reddit, etc. subsumed most other alternatives by offering what was for a long time a legitimately convenient and decent-quality service, but now that communities are too locked in to move (due to intentional measures like changing forking policy, and the community having to fight against network effect/SEO) they enshittify to squeeze out profit. Result is a worse site than if Fandom/etc. had never existed.
Relatively optimistic about movement towards structures that resist this kind of exploitation.
You can migrate wikis away from Fandom. The OP is about doing just that. The problem is that there's rarely the will because it's a hobby endeavor for tiny communities, and until you last as long as the Fandom alternative would last, it wasn't even necessarily the right thing to do.
You can't just migrate and call it a day. You have to stick around for another decade so people can find that information long after you've lost interest in the game and fiddling with MediaWiki.
Most of the costs are those that scale up/down by activity - MediaWiki itself is free/open-source and the wiki's content is contributed for free by volunteers.
Also, keep in mind I'm not saying that each wiki needs to be individually self-hosted. Can be a host the size of WeirdGloop but made up of smaller game wikis, for instance.
> I'm more concerned about the rest of the wikis like the example I gave where I'm googling for game mechanics for a dead game.
Prospects for long term information accessibility are pretty terrible on sites aggressively squeezing out all the profit they can. See Reddit eliminating archives and third party clients and then cutting off all search engines that don't pay, or mass deletions of user content by sites like Photobucket/Imgur/etc.
> You can migrate wikis away from Fandom. The OP is about doing just that.
With significant difficulty, fighting against both Fandom's policies and SEO/network effects. The OP lists "wiki communities need to be able to freely leave their host" as the primary rule for "How to not turn into Fandom 2.0".
> You have to stick around for another decade so people can find that information long after you've lost interest
Hence ability and willingness to pass on the torch is critical - so that the information doesn't die with one person or company.
— Something becomes popular.
— A $POPULAR_THING Wiki is swiftly created, some freelancers are hired to create article stubs. Links to it spread through other popular wikis.
— People trying to learn something about that topic get a lot of search results directing them to that new wiki. They assume that it's some kind of “community”, try to participate, and never realize that they're making love to an inflatable doll. Real activity, links and clicks now force the pages to stay on top, and attract even more naive visitors.
Of course, it's not specific to that site. “Social” sites often make people believe that they “interact” with thousands or millions of others, when in fact they shout into an empty box, and watch the movements of a primitive mechanism.
Take a random game like https://endlesslegend.fandom.com/wiki/Endless_Legend_Wiki
That game is 10 years old and its wiki was built in the height of its popularity when it had people to build it. The developer moved on, the community moved on. If its wiki weren't on Fandom, then its wiki would depend on some random person paying the bill for eternity for a game they themself moved on from long ago.
Yeah, it has ads, but someone has to pay the bill. I'll take the ad-ridden wiki that exists over the idealized one that went offline seven years ago when the interest died out.
This becomes a metaphor for the internet in general.