Starlink has about 13 million subscribers today and makes around 500$/year net on average per subscriber. It's still growing fast and will get faster and more reliable. You will also be able to use from your phone quite soon. It can very realistically get to 100 million subscribers which is going to generate 50 billion/year of profit. They have 0 competition in that space. Even if they make half of that it's still a 1 trillion dollar company right there.

You are saying "sub-fiber" but Starlink will likely be faster for long round trips once enough new gen satellites are deployed.

That comes before the whole datacenters in space conversation.