I think the difference now (in case code quality is solved with LLMs) is the cost of effort is now approaching zero.

Good enough AI is not cheap (yet). So at the moment it's more a scenario for people who are rich enough. Though, small projects with little maintenance-burden might be at a risk here.

But thinking about, this might be a new danger to get us into another xz-utils-situation. The big malicious actors have enough money to waste and can scale up the amount of projects they attack and hijack, or even build themselves.