A lot of manufacturing processes are easier without an atmosphere. Also low gravity makes it easy to launch completed product out to space for future space missions
We have plenty of earthbound motivation to solve the "energy too cheap to meter" problem. We're nowhere near that. Adding one more big energy consumer (moving cargo to/from orbit) does not make a material difference.
Starship is supposed (Musk hype warning!) to be 1/10th to 1/100th the cost.
We haven't done skyhooks or launch loops or launch cannons, which are large upfront projects but once built are semi-permanent economic gamechangers.
I always felt like that was a backwards justification for going to space (we want to go to space, how do we sell it), rather than a real need to that would push people to go to space.
Though the rather limited space on the ISS and its imminent decommissioning complicate that a bit. I think the current plan is to launch satellites for commercial production