> If this were the case, we would have plenty of complete Rust ports of Quake.

Well no, because there's little point doing it. You want a port of Quake 2 to Rust? Just ask Opus 5.5 to do it. I'm not going to waste the tokens but I guarantee it could do it with no further prompting.

It's literally a best case for AI - it can easily write tests to ensure bit-for-bit identical output and just keep going until it achieves it.

I'm not going to waste the tokens but based on the other stuff I've vibe coded, this was impossible 1 year ago, a difficult challenge 6 months ago, and trivial today.