Define “often”. Did you know that Elon isn’t chairman of the board of Tesla?

Also no, chairman isn’t only accountable to themselves. Where did you read that? Investor having seats on board is so they can have a voice in the direction of the business.

Activists investors often try to have a minority stake and a board member so they can force changes at the company -[0]. A recent example is Elliott’s effort at Southwest Airlines -[1]

[0] - https://www.investopedia.com/terms/a/activist-investor.asp

[1] - https://www.reuters.com/business/aerospace-defense/elliott-b...