> where is the challenge, other than complexity
Patience, for one. I reach a point where I'm looking at a mess of coal-fed sorters that need a complete rip-and-replace with electric ones, and that's usually the point where I close the game and go back to something easier like Kenshi.
I know it's a pipe dream, but these kinds of games (Factorio, Satisfactory, etc) would all benefit from sort of brain-game interface where I could just think about what I wanted to do.
The tedium and repetition is really what kills the enjoyment for me. The problem solving, planning, forethought, etc are super fun but it's killed by the former.