OpenAI had worse models (GPT 5.2 and 5.4) at that time. But now the tables have turned. Would Anthropic face a similar situation since Opus 4.7 falls below expectations?

Claude and Claude Code are still quite useful even when considering the recent degradations, so I don't think corporate users will leave easily especially considering that they're subsidized by their companies. I think the most likely scenario is that Anthropic will remove the Max ($100 / $200) subscriptions (which were the sweet spot for most users) and opt for token-based prices instead, which will make the average cost 2x ~ 3x higher which will keep them afloat in terms of ROI. Performance will plateau though since model research cannot sustain itself any longer, and then it's only a matter of how fast the open-source Chinese models will catch up in efficiency.