Yes to competition, but this isn't really that, this is plain vendor lock-in, and it is not really competing anywhere except within the Windows ecosystem itself

Yes to competition, but this isn't really that, this is plain vendor lock-in, and it is not really competing anywhere except within the Windows ecosystem itself, where it practically has a monopoly. If DirectX were to be used on Linux and macOS, you'd have some real competition, but that is not the case.