> Combine this with a big rural population, and Starlink has a great opportunity, if they can find customers who can afford it.

This is the rub. The primary market here are people whose communities aren't wealthy enough to afford infrastructure that would provide superior service (5G being a step up from satellite, and wired being a step up from that). So Starlink depends on there existing a growing population of people who aren't too poor to afford internet service in the first place, while also relying on the hope that those people don't become too wealthy to afford long-term infrastructure investments.