It's profitable if you don't pay for the rockets. The audited financials say the launch cost is $0 for Starlink (and -$whatever for Space [the launch business] but as depreciation over five years and not as direct costs).

So it's almost certainly the case that Starlink itself would not be profitable if it had to pay for its own launches. If Starlink paid for its own launches, the launch business would be closer to profitability but still not profitable, i.e. you'd have two unprofitable businesses instead of one.