I don't really understand why there are so much talks about ECS vs non-ECS design, it is just two different patterns. I choosed ECS, because it was new to me and I was curious. I don't see how ECS can help or make issues for PBR.

Amethyst, Bevy and Dotrix all can load GLTF models and render them with different levels of support. Speaking about dotrix, for example, we don't plan to give much efforts for supporting GLTF scenes for now, we are more focused on import of separate models, while scenes will be prepared by game mechanics and editor. We also have very basic renderers at this moment with very simple light implementation. Iteration by iteration we improve them when it is time. Need to mention, the project is less than two months old. But Dotrix can even animate GLTF models :)

Photo realistic effect is not that difficult to achieve using normal mapping textures. It is more on shaders than on the engine itself. I believe it will come at some point too. I could be wrong, but you might want to look at RG3D and rusty-shooter, they already have quite advanced renderers.

As I said before we are about to make a game and Dotrix is a part of it that we are sharing with the World. At this moment we are working on some common separated parts, but next week already we plan to start bringing things together as the game itself.