If people don’t know what the LLM behind the chat service is, then it seems likely (or plausible at least) that one could easily replace the chat bot used by these services with one backed by a different LLM, right?
Just like ChatGPT changes out models silently. Even if it's mentioned to the user, they don't care.
People just want a solution to their problem. Does a Google user care what iteration of their index engine they're using? No, they just want a picture of a god dang hot dog I tell ya hwat.