All good, but I suspect we're thinking about different aspects. If I understand correctly, you're pointing out that nobody is tied to legacy software any more - they can spend 37 minutes to re-implement from scratch in a safe(r) language.

My point is that everyone doing their own thing their own way means an attacker doesn't get the next thousand sites for free after finding a vulnerability in one site.

Having an LLM as sentry is a fun idea too.