Photorealistic 3D scenery advice - OpenStreetMap+satellite or Google/Apple 3D extract

Any advise on creating your own photorealistic 3D scenery? Two routes I've thought of.

Open Data

If we have satellite imagery, and we have height data such as from OpenStreetMap, we should be able to do something combining the two.

Obviously, without using stereo photogrammetry (multiple aerial photographs from enough different angles) we can't create proper sides of objects, because the data just isn't there. But, we could try various things like stretching the elevated pixels onto the sides, auto-generating the content based on those, possibly with some blurring and noise, etc. Impossible to get as good as Google's 3D maps or Apple's 3D maps, but might be better than just flat scenery with a few major buildings added.

Google/Apple Data

My brief understanding is that with giving them attribution, Google maps can be used for non-profit/non-resale projects. Maybe Apple is similar, I don't know. And, maybe I'm wrong about Google maps.

Anyone have a way to get Google/Apple auto-generated 3D maps into Prepar3D (or FSX or X-Plane?)

I don't get why there's a Google flight simulator, and Google hasn't capitalized on selling scenery packs for actual flight sims, for areas they have coverage on. (Granted it would likely need a high end computer.)