Elon Musk only controls 20% of Tesla shares, the board can force a sell upon him if the other shareholders agree on one.

And I'm not sure why Apple would buy a car company, it's too far of their core business (aka selling computers ranging from phone sized to desktop size).

The other car manufacturers are not blind idiots, they are seeing EVs are becoming a thing, but it's also in its early stages. The question for them is when should they start switching their line-up, and that's the difficult decision. Too early, and they end-up with too expensive and less convenient cars compared to IC vehicules, too late and you have basically miss the bus.