[petra]

What stops them? Mostly business considerations.

The differentiate their price according to features and so they extract more money. And by writing your code to specific peripherials, it's harder to switch to another mcu.

And they have large libraries of proven hardware peripherials and code which make it harder for competitors to enter. Why would they want to compete with open-source pio libraries?

The raspberry pi foundation doesn't care about all that. So they created this chip.