If I built a billion-dollar company why is this family stuff so impossible?

Because the family transition is a different kind of hard than the kind you've trained for. Building a company asks for grit, vision, and a willingness to act with imperfect information. Family transition asks for patience, listening, and the willingness to sit in discomfort without trying to solve it immediately. The two skill sets contradict each other in real ways. Kris Kluver, in The Dysfunctional Family Office, has Ryan tell Robert Mitchell exactly this. You already know how to do hard things. This is just a different kind of hard. The reframe matters because most founders interpret their struggle with family work as a personal failing. It isn't. It's a different muscle, undertrained because the success of your career didn't require it. The fix is to treat it the way you treated everything else you got good at. Practice.