There is a huge market even just in the US for Starlink. The worldwide market for people who need internet access in remote places is positively gigantic.
Additionally, Starlink could be hugely profitable if they exclusively sold access to ships and aircraft. You'll never be able to run fiber to those.
They can indeed reasonably charge $99/month to many many millions worldwide who don't have any options for low latency, high speed internet access. You vastly underestimate the need for the service.