Yeah, but that's also a large part of why they remain interchangeable, I would say. I feel like we may be talking past each other?

They are interchangeable maybe in your case. In my case for my tasks and for my product, Opus and GPT are at a level where I can vibe code with them and trust them, whereas the others aren't really there. When models get better they'll reach whatever point you need to be able to trust them.