The difference in the post-LLM era is that false identities can stand up a cohesive background and online presence with extremely little effort or human input, as many times as desired.

You took a cursory glance at a CV on a website and decided that was probably good enough to keep suspicion at bay, this time. But digging more and more to build up trust requires more time and effort than a bad actor trying to advance an agenda would need to put in; It is asymmetric.