Guessing by kids we’re talking about young children and not teenagers because old YouTube was practically made for teenagers. The more popular layouts people used back then often had the same aesthetic as myspace pages. There was more gaming content on the site than anything else, followed by viral vids (=3).
There’s a lot to dislike about the modern structure of the platform but as a grown adult I appreciate that there’s a much larger variety of content now which was essentially what the shift in design was supposed to achieve.