Because of COPPA <=13 year olds aren't allowed on youtube so they lie about their age. These youtubers perpetuate this lie because >=25 is a more valuable ad targeting demographic.

The brain isn't full developed until 25-30 years old. I changed a lot, mentally, in my late 20's to early 30's. 25 is still a borderline child.

Sure, but a lot of people are besides brain-dead slop-consumers.

That doesn't really challenge the proposal about regulating content.

(I personally recoil at the proposition of China-like content moderation but whatever.)

Algorithm moderation is not content moderation. A recent court case found that algorithmic recommendations don't fall under section 230 protection.