You essentially have to run in google to use them and that probably limits their ability to breakout. Anthropic might be doing this deal as a way to shore up their supply chain and cost of both inference and training by leveraging Google's hardware and chip manufacturing expertise.
every tpu thats been made is in use and sold at a high margin, demand is not the issue.
Several customers like Citadel, run TPUs in their own datacenters (closer to Exchanges)