The biggest competitor to Starlink is, ironically, traditional fiber.
When COVID hit, I knew a lot of engineers who decided to move to rural areas / small farms, because they could leverage Starlink to work remotely.
Last year, when I asked whether they still liked Starlink, all of them said it was amazing, but they had gotten fiber coverage in their area from a local provider, so they don't use it anymore, or just use it as a backup.
I think Starlink was a huge demand signal that there were people willing to pay a premium for faster-than-radio internet. So, unless they manage to be cheaper and faster than fiber, I don't think there is much of an endgame there.