As a current Starlink customer, I can assure you there's plenty of market outside of the "nearly ubiquitous". I live just 30 miles from a small city where the average home is served by 400Mbps cable, yet until Starlink came along I was stuck with Hughesnet, which is reminiscent of a particularly high-latency 56k dial up connection. There are a couple thousand similar households just in my county.
Trust me, I empathize as I am in a similar boat. But we are a small, small market comparitively. We are expensive to service, low density, and low profit. Pretty much the definition of a niche