That profit figure is a pre IPO marketing claim, not an audited and GAAP accounted number. And there is already a lot written about how Anthropic exaggerated revenue compared to OpenAI.
This seems like it's because openAI actually partnered with Microsoft and has to give them 20% of their revenue. Anthropic isn't partnering with their cloud providers so it makes sense to me they count top line revenue and then give Amazon payment as an expense. Also the numbers seem pretty minor compared to anthropic $49B run rate. The article mentioned an openAI payment of around $500M.