Exactly, when your business relies entirely on another business, you are taking a huge risk that the other businesses blocks you on a whim. There could be many

Exactly, when your business relies entirely on another business, you are taking a huge risk that the other businesses blocks you on a whim. There could be many reason such as randomly being flagged by some "spam" algorithms, or because add a feature that competes with your business, or they just don't like you. That's true for anything that relies on Twitter, Facebook, Amazon, Google, Microsoft, PayPal, ... You should always have a plan: what's the risk that X company terminates our account, what would the consequences be, and what do we do in that case.