The numbers aren't public but most guesses I've heard are that Anthropic's markup is around 50% on average, and that if considered in isolation, most models are profitable overall. The constant losses are instead due to training the next models, which will also eventually recoup but later, and forward capex investment.
This idea that big AI companies are normally and systematically selling inference at a loss as some kind of market share strategy is just not supported by the facts.