They had pretty drastic price cuts on Opus 4.5. It's possible they're now selling inference at a loss to gain market share, or at least that their margins are much lower. Dario claims that all their previous models were profitable (even after accounting for research costs), but it's unclear that there's a path to keeping their previous margins and expanding revenue as fast or faster than their costs (each model has been substantially more expensive than the previous model).
Well how much of it is correlation vs causation. Does the next generation of model unlock another 10x usage? Or was Claude 3 "good enough" that it got traction from early adopters and Claude 4 is "good enough" that it's getting a lot of mid/late adopters using it for this generation? Presumably competitors get better and at cheaper prices (Anthropic charges a premium per token currently) as well.