There are competitors: The Linux phones (pinephone, librem). In fact, privacy has been one of the selling points of desktop Linux forever. The problem is it doesn't sell, or at least it hasn't till now.
This is what Apple is trying to change, basically convince people (through ads) that they need to care about their privacy, because they know it's a competitive advantage they have when compared to the other big companies.
Privacy was also a selling point of BlackBerry/RIM and was successful but it’s hard enough to convince people it’s worth switching over to Firefox from Chrome so I think you’re right.
It is interesting that Apple can market themselves as protecting our privacy if for no other reason than all their competitors do the bare minimum.
