The only thing I see wrong here is the sexualization, but it'd be us doing it if we assume the reason of the timestamp. Compare: Video of people playing soccer, someone adds a timestamp to a part when a guy passes the ball to another guy, would you think the timestamp was created because of sexual arousal and tell they need to see a psychiatrist? How is kid doing squats different?
These videos exist, people like to watch them, but I don't see people assuming the intent is for people that have some cat with yarnball fetish to share it with others that do, as the context. Nor were the children eating the lollipops intending for anything else than having fun. There's nothing wrong with either, other that people assuming why people upload videos, watch them, timestamp them, or share them.
In reality, I could have in my mind someone that gets aroused by... maraccas (I don't know, it's the most mundane thing I could think of). There's a maraccas video, and there's a comment with a timestamp that says "this is why you're here", so in my mind, there's this group of people that get aroused by maraccas and this comment is for them. The intent and context is clear. All this fabrication is not less real that yours.
Chances are there's a guy out there that actually matches the pedophile in your mind, however, they're not wasting their time clicking timestamps on youtube. If you research porn, people get adapted and need worse and worse things to "get on". The actual pedophile stopped being impressed by such timestamps content long time ago.
The worst part is that I disagree with his claim, or rather I don't think he makes a strong argument that these videos are _intentionally_ sexual. It looks to me like a kid doing kid stuff. I might have made the same videos at her age _but_ it is still sexualized by some people.
I am not sure what's a good solution to that could be. According to these new articles, it looks like any video showing a kid is potentially sexualized.
Banning all kids on youtube look a bit extreme and would raise its own set of problems. And at this point, just having a kid in any movie/series has the same consequences
So yeah .. not sure we can stop that. And if you are sharing timestamp of kids doing squats, you are probably too far gone that just asking you to see a psychiatrist is enough.