Why would experienced devs join a vibe-coded project that barely works to overhaul it? Most of the time it'd be quicker and easier to start a new project from scratch with the same goals but coded competently.

You're bending over backwards just to come up with a plausible-sounding excuse for vibe-coding. But unfortunately, "plausible-sounding" isn't the same as "plausible".

Vibe coding might be "good enough" for a tiny private project for someone who doesn't know how to code and isn't interested in learning. But LLM's aren't good enough to build usable architectures.

And all publicly available human-created code was already trawled years ago, and the creation of more is slow. LLM's can't get significantly better at coding by just throwing more data into their training because there is no more data left that isn't already in the training.

The era of not judging the means ended in, like, 1066 or smth. Vibe-coded stuff for example means burning down a couple of forests just so the AI can propose where to place a semicolon, long before a "result" is even visible.