As you correctly mention, the CPU providers aren't the ones who are responsible for the scaffolding that ensures security in programs. The CPU cannot decide if

As you correctly mention, the CPU providers aren't the ones who are responsible for the scaffolding that ensures security in programs. The CPU cannot decide if an instruction is safe or not, and the same is true of LLMs. Think about SQL injection - we did not change SQL the language, but how we utilize it in backends. A lot of people (thousands) outside of the LLM providers work on the problem of Prompt Injection, both in industry and academia. We aren't even at a point where we can reliably detect it, let alone prevent it. Please, if you have a mental model of how scaffolding around things like instruction or SQL injection could be used for LLMs, I'd like to move on to all the other (less pressing) security issues we have because of the AI revolution.