To be honest, this predator catcher thing has always been cringe. It has always been ill-intentioned people masking their poor behavior by using a subject that everyone agrees is evil as their opposition.
The unpleasant truth is it's as close as you can get to actual justice without simply giving into pure vigilantism, which, I must admit, is growing more and more appealing and seemingly inevitable as time goes on. We've seen time and again (with and without the antics of these catchers) the authorities literally ignore obvious crimes until overwhelming evidence in easy cases are literally spoonfed to the useless fuckers. We've seen time and again courts (and especially juries) are wildcards, letting perverts go free even when the prosecution has them dead-to-rights.
This will eventually devolve to police lazily trying to solve murders of men found alone and dead in their pickup trucks or cars, with bags of candy, lube and condoms in the glove box and stab or gunshot wounds, along with manila folders containing chat log printouts of naughty conversations. When this predator catcher trend wears off and they stop trying publicly (because as you say, it's largely for clout chasing and fame, not to actually solve a problem), people who care more about stopping predators than fame (or infamy) will just start taking care of business.
The message will be clear enough, I suppose. Whether the police bother investigating that kind of vigilantism will depend on which offends them more -- people doing their jobs for them, pedophiles being killed, or pedophiles trying to abuse children. The former two will light a fresh fire under the authorities' asses, while if they get the right message and settle on the third, those cases will just go cold. Never forget the lesson of Gary Plauché, who killed his son's rapist with a single gunshot to the head at point-blank range at an airport as police were leading the pervert from a flight to their awaiting car. He immediately surrendered after firing the weapon and dropping it, stood trial, pleaded guilty, and never saw the inside of a prison. The system tried to punish him for defending his own son, but it couldn't force its will even upon the judge and prosecutor who went through the motions but wouldn't actually put him in prison.
People don't have the stomach to punish vigilantes anymore. Not with this dysfunctional "justice" system failing us.
It's not ideal, but it's the closest to real justice most of these perverts will ever see.