It might not seem like the case right now, but I think the real disruption is just about to begin. OpenAI does not have in its DNA to win, they're too short-sighted and reactive. Big techs will have incredible distribution power but a real disruptor must be brewing somewhere unnoticed, for now.
I'd say the lack of a narrative from the board, general incompetence with how it was handled, the employees quitting and the employee letter played their parts too.
But even if it was Microsoft who made this happen: that's what happens when you have a major investor. If you don't want their influence, don't take their money.