Speaking of Three.js, have you heard of PlayCanvas (https://playcanvas.com)? It's pretty much a Unity-like IDE based on Three.js, and allows a whole bunch of cool features, like live collaboration.

Here's an example game made in it: Tanx, https://tanx.io. And here's a lightmap-heavy scene for eye candy: https://playcanv.as/p/txPePQvy/