The crucial part is security.

If the apps runs locally it doesn’t matter, if it‘s connected to the net it could be the seed for the next Mirai bot network.

Apps running locally can also be subject to security issues. What you're trying to say is probably "apps not using untrusted input". If an app takes no input all, I guess we could say that security isn't an issue, but there could still be safety issues.

It’s a pretty good solution for creating live mockups. A designer on my team came back eight hours after a meeting with a fully vibe coded, multi-page interface. I was honestly blown away. I had no idea this was the state of what’s possible with these tools.

Was it a real website? No, but it’s a live mockup way better than any Figma mock or rigid demo-ware.

Oh I'd never argue that. Cloud stuff is truly beyond the complexity I'd get involved with at the moment.

Also design. All the vibe coded apps always look like absolute ass.