Well, they can try it out and see if it does what they want.
Tests can't be exhaustive, whereas even a mediocre developer is likely to possess enough background knowledge to notice risks that a non-developer would not think to test.
Some people keep forgetting that we haven't reached AGI yet. These tools can still make serious and sometimes obvious mistakes. Not long ago, vibe-coded software could embed credentials directly. That particular blunder seems to have been addressed, but there is still no reliable way to tell an LLM to avoid every class of obvious blunder.
As for AI fixing things... Sure, at least for a while. But in my experience, AI can hit a wall and start going in circles. It doesn't happen often, but it can happen. And when it does, what recourse will you have for fixing the tangled mess that vibe coding tends to produce?
Is that true anymore when anyone can vibe code? Seems to me that quality, correctness, and performance will be huge differentiators in a see of vibe coded slop.