It sounds like an excellent platform for artists who might not have a lot of coding skills to contribute graphics toward. Kind of the point, in my mind.
Any serious libre gamer with a big graphics card to test would just launch Flightgear at 4K with the ALS effects on, real time weather and a crazy draw distance over 30 kms with all the shading FX' on. And lots of tweaks that made clouds looks like clouds and not fancy textures or barely recreated shaders.