I realise the major point of the game is to manage money and create a profitable business but…
…I’m playing this for fun, I do all of the boring stuff at work and I just want to create an efficient factory and see what all of the research branches do.
Nearly all sim games I’ve played have either a sandbox feature or a level/game that has no money involved and another mechanic to dictate completion. For production line this could be x number of cars completed in x time or achieve a takt time of x in x time.
I would end up playing level after level of this to achieve an efficient factory, I can’t tell you how many levels/hours of Factorio I have played just to try new layouts or processes.