This is widely accepted business theory. It’s hard to innovate when you depend on suppliers external to you for key technology.

I'm fine with this. Apple can extend sucky BT, Apple can make their faster Apple Silicon chips, Apple can make iMessage since SMS is trash, Nvidia can do CUDA cause OpenCL sucked, whatever. Just don't also intentionally kneecap the competitors by removing their interfaces.

That is very different from saying "Almost all innovation comes from this type of vertical integration."

Innovation comes from many sources and while vertical integration does assist in some cases, your assertion steps so far past plausible that it is simply ridiculous.