There are two chairs on a construction project. In one, you're the general contractor: every trade, every schedule conflict, every inspection is yours. In the other, you hire the GC and manage from above: same accountability, different altitude.
The ability to sit in either chair changes everything, because the choice becomes about the project instead of about your limits. Small enough, and self-performing keeps the margin and the control. Past a certain size, the GC seat stops scaling. The correct move is to hire it out and manage the manager, and I learned that one the hard way.
Managing the manager is its own trade, and it only works if you've sat in the other chair. A GC quotes differently to an owner who has run sites. Schedules get honest when the person reading them has built one. The change order conversation is a different conversation when the owner knows what the work actually takes. Nothing disciplines a bid like the quiet knowledge that the client could self-perform if pushed.
Owners who have never held the first chair pay for it invisibly: in padding, in schedule slack, in problems discovered late because nobody knew which questions to ask early. The chair you've sat in is the one you can't be fooled from.