And the cheapest engineering firm won't use LLMs as well, wherever possible?

The cheapest engineering firm will turn out to be headed up by an openclaw instance.

fun fact, LLMs come in cheapest and useless and expensive but actually does what's being asked, too.

So, will they? Probably. Can you trust the kind of LLM that you would use to do a better job than the cheapest firm? Absolutely.