who cares at that point? At that point, do what you love. If what you want is to win a national championship, then yeah you may need to go somewhere else. If what you want is to just build a legacy here and you like living here and your family is happy — then why not stay here your whole life?
The average faculty member at BYU is there for 33 years before retiring. Many of those could have made more money if they transferred around to other universities, seeking pay bumps each time. But they don't ... because other things matter in the equation.