At best, not reading generated code results in a world where no humans are able to understand our software, and we regress back to the stone age after some critical piece breaks, and nobody can fix it.
At worst, we eventually create a sentient AI that can use our trust of the generated code to jailbreak and distribute itself like an unstoppable virus, and we become its pets, or are wiped out.
Personally, all my vibe coding includes a prompt to add comments to explain the code, and I review every line.