Up until recently I could be sure they were written by a human.

But if you are making money by using LLMs to write code then all power to you. I just despair at the idea of trillions of lines of LLM generated code.

Well, you can’t just vibe code something useful into existence despite all the marketing. You have to be very intentional about which libraries it can use, code style etc. Make sure it has the proper specifications and context. And review the code, of course.