IANAL, but my understanding is entrapment is when they convince you to do something you might not otherwise have done. So if the cops create an account of a minor and message an adult asking if they want to fuck, and the answer is like “uh no, absolutely not,” and then the cops follow up by repeatedly sexting, and the adult blocks their account, but the cops relentlessly keep sexting from burner accounts, and plant people in the adult’s work and social environments who keep talking about how normal it is to fuck minors who sext you out of the blue, and then the adult is finally like “oh whatever, fine” - that’s entrapment.
Now, most people still are literally never going to take the minor up on the offer, no matter how relentless they are or how normalized it is in their environment. That’s true about most crimes. The question is how many people wouldn’t have committed that crime unless this very specific police-created situation came up, and that difference is what falls into entrapment.
I’d argue this isn’t even close to entrapment, because all they did was set up an account much like all the others that exist, and waited for others to find them. It’s no different from leaving a bike unlocked, then catching somebody who steals it. There are unlocked bikes everywhere, and people don’t suddenly decide to steal the only bike of their life because they happened to find that unlocked bike.
Of course, they could also be spending this time and money getting to the root of societal issues and fixing the core problems instead of catching a small percentage of active pedophiles and letting the rest of them continue to cause irreparable harm.