Sometimes it feels like there is an awful lot of software out there that shipped without much review. This was happening long before AI arrived on the scene.

Hard to tell if anyone was 'comfortable' with that.

You get confidence in things by doing them. If you don't have experience doing something, you aren't going to be confident at it. Try vibe coding a few small projects. See how it works out. Try different ways of structuring your instructions to the 'agents'.

You don't. Whoever's telling you those stories has a very long nose.