>>8216776A couple reasons:
Kids are an unreliable audience. They won't stick with you
Kids are not good at navigating youtube to find content they want. They rely entirely on the algorithm for discovery. When the algorithm stops pushing you, kids abandon you and you stop getting new ones
Youtube is stricter with your channel when it thinks your audience is kids, leading to enforcement action for content that doesn't infringe its content policies. The algorithm doesn't care if your last 5 videos got low views because you were shadowbanned by the algorithm, it only cares that your numbers show you're no longer "hot"
Appealing to children greatly limits what content you can actually deliver without alienating them as an audience. You have to avoid adult themes, foul language, things rated more than PG13, etc. You're a prisoner to a PTA mom's concept of 'objectionable'
Kids are insufferable and drive away adult fans that A: don't want to deal with kids and B: don't want to be seen as willingly participating in a child-centric hobby. What you're left with is the kind of people that called themselves "bronies" unironically, further stigmatizing your fandom.
Exploiting the young and vulnerable is a good grift for separating wealthy middle-classers from their money but it's not an industry suited to the honest or in general people that don't take genuine joy in being awful human beings. Leave it to Hasbro and the catholic church.
