There are quite a few providers of inflight wifi via satellite (or even cellular towers). Speeds are not usually as high as Starlink but it is ridiculous to say they have zero competition.

You also have Amazon building a constellation, OneWeb with one already in place (though not available for retail customers), and a Chinese one under construction.

I don't know who else is launching satellites, but many airlines do offer wifi, often via partnerships with telco companies. It's just expensive and slow.

So the only moat I see (as a layman) is the speed and capacity. The one flight that I was on that had Starlink, had better internet during the flight, than most airports have on the ground.

Amazon Leo has about 350 in orbit now, on their way to 7,500.

ASTS - though I think their satellites are supposed to connect to phone hardware