There's also the issue of scaling. Say you can make the engineering work for building a data center in space.

Nobody wants to build just one, or even just a handful. Musk has talked about 10000 launches a year for deploying and maintaining data centers.

At that scale pollution becomes a serious issue. It hasn't been a problem so far because we haven't launched a lot of rockets. Cumulatively the world has under about 8000 orbital launches and under 40000 launches that were not orbital but reached the stratosphere.

Orbital rocket emissions have an impact far beyond what you might expect just from looking at the mass of what they emit, because they emit much of it the upper atmosphere. Many things that when emitted near the surface are only a local problem become a global problem if you emit them in the upper atmosphere.