This assumes you can refine the ores "in orbit" and manufacture everything "in orbit". This in turn requires a ton of manufacturing on Earth and a lot of launch

This assumes you can refine the ores "in orbit" and manufacture everything "in orbit". This in turn requires a ton of manufacturing on Earth and a lot of launches to move all this stuff off Earth. Not to mention all the supporting industry and infrastructure manufacturing normally has on Earth. Not to mention the R&D costs and staff logistics. This isn't a video game. You can't just click a button and have an autonomous satellite factory churning out satellites in space. Moving any amount of manufacturing or refining into space is a massive logistics undertaking we haven't even begun to explore. Just because Bezos has a vision of moving the working class off Earth or Musk made some off-the-cuff remarks to rile up his yes-men, that doesn't mean this is something that will happen soon, much less something that will be useful soon.