That’s kinda what I was trying to point to. Yes it is a lot of work to replicate the functionality, but apparently Valve has no intention of “plugging the hole” this data is coming from, and I’m not sure NexusMods would have any ability to torpedo any potential alternatives as they also depend on a third party. So if/when the original enshitifies it would be possible to move on to a new platform.

What’s special about SteamDB that no real, fully fledged alternatives showed up yet? What would prevent someone from “forking” it?

They sometimes also provide alternative versions of games. I was very happy to buy Kane and Lynch (1 and 2), but the co-op feature is missing (both local and online). I guess that part was licensed differently or something