Firstly, entrapment, legally speaking, only applies when the police are doing it.
Secondly, entrapment involves *inciting* someone to commit a crime that they wouldn’t otherwise have done. Catchers don’t initiate the contact, and should be up front about the age, do not initiate sexual talk etc.
Police can also operate “stings” in this same way without it being entrapment, and prosecutions do happen.
During the first TCAP sting there was no police involvement at all and the people they caught all had their charges dropped and cases dismissed by the judge, who literally cited illegal entrapment as the reason for it
They also frequently do. The groups TCAP had working for them were guilty of both of those things and many other violations and flat out lied and tried to hide it by faking a harddrive failure when ordered to turn over chatlogs. Those same logs later appeared in edited form on their website
Point is, none of these groups are above board and they all do sketchy shit. Thats what happens when you get into vigilante behavior