Unless you use your oen local models then you don't even know when OpenAI or Anthropic tweaked the model less or more. One week it's a version x, next week it's a version y. Just like your operating system is continuously evolving with smaller patches of specific apps to whole new kernel version and new OS release.

There is a huge gap between a model continuously updating itself and weekly patches by a specialist team. The former would make things unpredictable.