Is the Mythos security capability improvement a single discontinuous jump, or a new reality?

You could argue that there's a backlog of old software that all needs to be fixed up at once… but that's a one time thing.

New software that is exposed to Mythos before shipping simply won't ever have the same problems.

Or, it could be that a new equilibrium has been reached, where machines can find vulnerabilities faster than the human clock speed.