One thing to think about is that the heating/energy is exponential. So doing the belly flop lowers the heating and the energy the rocket is carrying quite a bit

One thing to think about is that the heating/energy is exponential. So doing the belly flop lowers the heating and the energy the rocket is carrying quite a bit. Planes make 90 degree turns all the time! And in actuality this rocket could be less complex than a modern airliner as far as number of parts and processes. They have taken huge leaps in engine technology with Raptor that allow for a lot of simplification across the rest of the rocket and which could make it airliner level safe someday.