Realtime soft lighting is possible but at what cost, for such static scene? I think the light bake technique he used is, in fact, the appropriate way to get beautiful visual results with the upside of good performance in any hardware. It's curious to say Dunning Kruger effect when I do believe the decision reached is possibly conscious about the performance shortcomings of bouncing light in real time
Most studio or developer I know that works with 3D in web always use baked lighting. Realtime always cost more especially on mobile.