But that said, I've worked on/at many (many, many, many) projects/companies that are dependent on someone else's ecosystem to be viable. Sometimes it's about traffic. Sometimes it's about behavior (e.g. they change an API without giving you a heads up). There's money to be made in those ecosystems and often times the owners of that ecosystem care a lot about their partner network...until they don't.

Worst of all, they really aren't beholden to keeping your lights on and you should realize that when entering a (often implicit) relationship with them. It's just the way it works.