They probably could find "a competent CEO", but that's not the bar, and it doesn't make sense to do so, because of the oversized impact and risks. If you're 99% certain that a person is as competent as the current CEO and 1% they're a dud like Carly Fiorina, then saving a measly $100m is not worth the enormous risk. And if you've got a candidate that makes you certain that they're even slightly more competent than Pichai, then it would be worth paying an extra $100m to get them.