This is super impressive! I'd agree the open-source tooling isn't there yet, but it's coming in a few places. I started a 3D street visualizer but it's only at the scope of a few blocks at a time, not as large as a city area although we'd like to get there someday: https://github.com/3dstreet/3dstreet/

There's also https://github.com/a-b-street/abstreet for larger area simulation but with less visual fidelity