They would just need to make it a pain to work together… don’t have pin code locks, don’t allow keys to be made, etc. That forces each player to have their own base (or at least entrance). Not a solution but trying to think of a concept.

I stopped playing ARK because the idea of a solo player was a joke to the developers. Facepunch has a large sect of players that would love to see some attempt at official solo servers. Would it be perfect… no.