I think people like this really betray their lack of real world friends, socialization, and especially contact with women...
First of all, everything cutesy is not pedophilia because "the behavior is very child" or whatever his dickless friend was saying. People making "pedophilia" a meaningless term just because they want the little dopamine shot of condemning someone and feeling righteous whenever possible is absolutely awful, for obvious reasons. I know they've probably never spoken to a woman outside a discord call or a college struggle session, but VTubers, being portrayed by actual women, tend to embody what an actual woman would like to be. Some want to be cool, some want to be sexy, and some want to be cute. Being cute and innocent may be traits associated with children, but they're not exclusive to children.
If this dude (somehow) actually dated a woman and she started getting cutesy with him, is he gonna flip out and go "how dare you accuse me of being a pedophile"? if she refers to chicken as "chimken" or a snake as a "snek" is he gonna bust out with "um, excuse me, that's not how an adult speaks!" Women love cutesiness you absolute twitter-brains. There's something equal-parts amusing and infuriating about someone being so smug in their utter ineptitude.
On another note; yes, forced fanservice can be cringe, but how the hell are you gonna react to it he way owl boy here does where he groans sheepishly like his racist grandpa just called his mixed-race friend a slur?