It does not make much sense to finish the engine, especially in the today's market where you often have to make smaller games with a small budget.

Indeed, for people who's goal is to finish a game and sell it , even a casual game, they can't spend programming tools or learn shaders , specially when there is lot lot of stuff onto HUD, menus panels , molde,s textures, animations etc ...

I like to use standard shaders (normal map, toon shader, , water ,refraction, HDR etc ...) , i just want theses standard
to be available, but i'm not interested at all to program shaders !
So yes some times a visual shader editor is better for non
pure programmers !