You are correct, but that doesn't invalidate anything I said. If someone is a great CEO for you, and they tell you they will retire to a less stressful job unless you pay them $10m it is worth it, even though you know next year (and $10m richer) they will retire. Their success over that one year should more than make up the money you spend.

Of course this assumes that one more year of development is required for the next CEO to be ready. Great CEOs try to have a replacement (or several) in training at all times.

Note that I'm assuming a great CEO - most are not great.