It's definitely a gamble building your business on top of another, much larger company's product.

It's called platform risk, and while every company has it to some degree, if your business is solely dependent on a third party especially one that doesn't have (much) skin in the game (your game, not theirs), that risk becomes existential for your business.

I've seen it before where a company builds something cool, only to be shut down by the larger company who for whatever reason doesn't like what the smaller company is doing.