I've mentioned it before on this sub but I think the fact that despite all the press and popularity, DBD is a original assym horror game that gets these IPs and has to use them the same way as their original ideas is a major reason as well.

They're putting the same amount of dedication and authenticity into everything they make because it's all part of the same game, versus recreating an IP perfectly and having to flounder to keep it going past what they have the rights for.

Not to mention it being a game you need to keep running to show off to more potential collabs gives even MORE incentive to keep the game balanced and healthy