Can you elaborate on what's not good about eevee/cycles shaders? By proper integration do you imagine it will use Blender's node shader system or a different system?

I'm not being combative, I'm in the process of learning enough of Blender's code to be able to contribute.

I could write a book about this, but to make it short, what most users of a 3D system like Blender want when they get to the shading/rendering part of their work is to simply:

   - pick an object in the scene

   - pick a pre-made rich and complicated shader (wood, glass, tar, etc...) from a huge library of shaders expressed in a standard form (as in: that will work with whichever render, be it cycles, luxrender, moonray, etc...)

   - drop it to the object without having to screw around for hours with texture scaling, rotation, uvs

   - rinse and repeat until all objects in the scene are shaded

Very few people have the skills/knowledge and patience to put their own shaders together themselves by assembling basic nodes into a large and complicated shader tree.

There has been some (feeble) attempts to build standard libraries of Shaders around Blender:

https://github.com/LuxCoreRender/LoL

https://www.youtube.com/watch?v=mCShkpW1c2w

These are:

   - hard to use

   - not always free

   - not standard and portable across renders

In practice, assigning materials to a large scene in Blender is still a giant, time-consuming PITA.

I've used Blender only a little, but surely you're aware of the Asset Browser introduced in the 3.0? They seem easy enough to use, but of course they'd need to be high-quality to work similarly with all renderers.

Granted I don't actually know where to find such libraries except for the small free asset bundles at https://www.blender.org/download/demo-files/#assets or perhaps by paying Blender organization for them, so maybe this doesn't really address your core point :).