1. Stock options aren't long-term enough – a CEO can make a series of decisions which increase profits and therefore increase stock price in the short-term, but completely hamstring the long-term viability of a company. Doesn't matter though, the CEO already made their bag and moved on.
2. Even when the chickens come home to roost when the CEO is still there, the market is not properly punishing underperforming CEOs. For whatever reason (I have a number of theories), a CEO can do an objectively poor job, leave their current position, and then somehow end up at a different company in a similar position of power not long after. You have to do a really, truly terrible job and even then you might not be out (just look at Adam Neumann).
3. Comp is so high these days (because the multinational corps have gotten so big even when the number of CEOs per company mostly has remained at 1) that even if you do somehow (a) torpedo your stock options and (b) become unemployable, you were probably making enough that you can live out your days very comfortably if necessary.