Product CEOs are intimately familiar with their products including design decisions, code quality etc. This creates an attachment to get a little too involved in implementation details even as the company is growing beyond say 100 people. One way to get a bit detached is to be deeply involved in hiring people and coaching technical leadership. By thinking at a meta-level it is not hard to arrive at some process that can be documented that teams can self-manage well enough for product CEO to let go.