The challenge there is competition. If other providers can match or beat their model quality at a lower cost that revenue could dry up pretty quickly.

Or as Anthropic put it on page 42 of their S-1: https://www.sec.gov/Archives/edgar/data/2130357/000162828026...

> If we are unable to differentiate our models, platform, and applications from competing offerings through enhanced functionality, superior performance, better safety features and reliability, lower cost, or other factors, demand for our models, platform, and applications may decline. The rapid pace of technological change in AI means that models, platforms, and applications can quickly become outdated. We must continuously invest in research and development to maintain our competitive position, but there is no guarantee that our investments will result in models, platforms, and applications that customers prefer over competing alternatives.