Vibe coding from scratch is far from translating an existing app to another language.
I don't know any bad stories about ai-translated apps. Partially because it's a relatively new trend, but also because a big amount of usual vibe code fail modes are not applicable here.
We are still far from it. Same issue as with robots: you have to build a new environment to let them work efficiently, or at least severely adjust the existing one.
This will be the next step, and it will be nasty: changing our workflows to "agent-friendly" even if they less convenient for humans. And then - yes, partial replacement.
I don't know any bad stories about ai-translated apps. Partially because it's a relatively new trend, but also because a big amount of usual vibe code fail modes are not applicable here.