The thing about the og content cops is that they were never supposed to be these epic, career-ending and well-researched takedowns of the people he covered, that's just the reputation they gained after channels that were much bigger than Idubbbz were significantly affected by them (temporarily). Content cops were nothing more than Ian taking a youtuber/youtube trend he didn't like and going "this is cringe and I hate it, let me tell you why" interspersed with funny skits, and it was a breath of fresh air at the time. They would be a breath of fresh air now more than ever tbh.
The biggest reason why they worked so well wasn't because they were well-researched, but because he was a neutral third party who didn't moralfag, but rather unapologetically hated on his targets and painted them as embarrassing and pathetic instead of evil, which made them into laughinstocks, while also being entertaining and charismatic. For a good example and contrast of this we have the video Ethan made on Leafy back then, where he just preached about Leafy being a mean bully and presented himself as morally superior, which was received so poorly he had to take it down (Ian should take some notes). Then on the other hand there's Ian's content cop on him, where he was just making fun of the guy and his videos without touching on morals at all or making himself out to be the better person, and it did so well Leafy's viewership got halved after it released. Another big thing that made them effective and that has been completely eradicated is that there was nothing to attack Ian on, because he was always in character and never exposed any embarrassing details about himself nor did he get involved in any retarded drama, the opposite of Ian today to an insane extent. You should also keep in mind that not only did he consistently attack channels that were bigger than his (with the exception of Tana), but he also got the clout needed to make his content cops impactful from two factors: hanging out with the cancer crew and the content cop series itself, specifically the Keemstar content cop. I dare to say that the Keemstar content cop, and later the Leafy one, launched him into mainstream success more than the cancer crew collabs. He got the clout to make content cops from the content cops.
You say h3 isn't an easy target but I very strongly disagree, they were prime content cop material even back in the day, the reason why they're above Ian's league now is because Ian has been mind-raped so thoroughly that he doesn't know how to effectively dunk on people anymore, and he's also guilty of everything he could attack h3 for, tenfold, so he's without a sword and a shield. If Ian had kept his personal life to himself all these years and didn't let Anisa and her terrorist friends control him, then he could have made a good CC on h3, because there's seriously a lot to talk about without even getting into politics.
That all being said I have to add that watching the type of repulsive worm he's become has really diminished my enjoyment of his old videos. What a shame.