Only the big tech that donates large sums of money to Tramp (which seems like most of them)

Putting aside how much of a red flag that is,

Is there any foss self-hosted version of these location sharing services?

In addition to other’s comments, I think that we just have enough good games by now that a lot of people can find a game they enjoy enough to sink hundreds or thousands of hours into. Minecraft, Factorio, Satisfactory, Hollow Knight, Elden Ring, etc.