This is probably going to sound elitist, but it is how I've been seeing this whole LLM thing play out.

I don't necessarily believe in 10x devs, but there is a very clear output difference between various developers. During my career I've been both in a position where I was delivering much higher quality code at a similar pace to other coworkers and also mediocre code at a slower pace. Sometimes at the same time.

Now, AI itself is a force multiplier. Depending on the task, your setup, your skill level (both as a developer and with LLMs), the weather, the model and so on, it can range anywhere from actively hindering you, to solving the entire thing for you. Let's say that on average you get a 20% productivity boost.

If you take a 0.8x developer and give them a 1.2 force multiplier LLM, you get a 0.96x developer. Worse, the axis that has moved is speed, not quality.

All this to say that if you let a below average developer vibecode, you get a much higher volume of slop. You can make an agent create good code, but this developer didn't care before so why should they now?

*Note that this is from experience. I've started getting feature PRs from our devops team. It's been a very enlightening experience.