[henearkr]

Yes, and also there is a limit to what we accelerate within Earth's atmosphere, as it tends to burn up from friction.

So yes, the simpler machines on Earth are mainly useful at first as a bootstrap, and after that it would rather be from the Moon or Mars as a hub, with huge electromagnetic railguns.

Between Earth and low orbit, maybe some version of a space elevator could finally see the light?

If we follow this kind of blueprints, prioritizing electromagnetic tech instead of fossil fuels, we can successfully bootstrap some amount of space-based industry without trashing too much Earth's liveability.