Yes, you can. It was easily done.
My family, in fact, owned the city of Beverly Beach, Florida for a period of about a decade in the 1970s. My grandfather and uncle bought a parcel of land along A1A, bordering both the Atlantic Ocean and the Halifax river. It was in the sparsely-populated (then) unincorporated township of Beverly Beach, and their plans were to develop a campground and mobile home park.
However, the land purchase was so large we had to apply for the same government district that Disney had, because, when complete, our mobile home park would effectively be Beverly Beach as 70% of the population eventually lived there. So, part of our agreement was to install a water treatment plant, a sewage system, electric connections for all residents in unincorporated BB outside of our district, etc. Our mobile home park had to build an extra large meeting center as it doubled (at that time) as the city town hall. We even laid the first cable coaxial lines for the residents. The exemption was temporary… 20 years, I think, and I don’t think it was kept by whoever we sold the campground to, which is not surprising: the district had outlived the usefulness of the business model.
My family literally built a city using private investment and yet here you are… a ‘conservative’… asking is it right to build a city for private investment? Really?
Anyway, to your question, as for now one likely can still do this if they show Ron De Satan that they have the correct GroupThink.