Probably not any of the content cops. I'd say Ian started shifting away from his old self when he started doing those "documentaries" namely Full Force. Anisas poisonous influence definitely had a huge hand in shifting away from being actually entertaining since she's a pick me who will emulate whatever she perceives as the popular thing now. (She definitely loved being edgy when she first seduced Ian but now the brown man she likes prefers lefty politics so now shes that)
The Sam Hyde video is just most notable because its definitely the video that completely destroyed Ians ego. Up until that doc, Ian had successfully demolished any idiot that stood in his way and Full Force, which lets be honest is just a doc meant to put eyes on a fat retard for everyone to laugh at, was also met very positively. Since it didn't feature any of his old edge, Ian considered himself past that version of himself. At this point, Ian thought he was totally invincible and, by Sam Hydes words, "the puppetmaster" when it comes to his projects.
Ian believed that silly old Sam Hyde, that dipshit edgelord clinging to the past would also be some retard he could make a doc on and prove how much of a loser he was. But Sam was far smarter than him and dogwalked his stupid ass hardcore. That cuck chair confrontation you can watch in real time as Ians ego shatters into pieces and he's never recovered.
After that, Ian was basically totally overtaken by his wife, knowing now just how fragile and weak he is. So now we have our hollow called Idubbbz wandering the wastes of the internet, his limp marionette strings being danced by Anisa. At least til the Tattoo money runs out and she bails.