Or rather it's being.. Unsubstantiated. The Nerf conspiracy isn't that there have been a few harness and platform bugs leading to performance regressions, but that OpenAI/Anthropic have maliciously and unethically degraded their model performance post release to shed load and save money.
To me that sounds exactly on-brand for Big Tech in general and Sam Altman in particular.
Yeah it's just inconceivable that companies whose entire business model started by engaging in wholesale for-profit theft and abuse of intellectual property would ever be so unethical as to try to lower their costs, especially just prior to an IPO.