Obviously it is more complicated. The first step is simply “don’t hard pull the front brake in panic.” For a small child, complications beyond “squeeze this and that to stop while maintaining scary balance” is already complicated at first.

I’m a former buyer for a chain of bike shops. You have no idea what I’ve seen. Kids can be incredibly stupid. They are generally fast learners, and it is easy to forget the earliest learning steps. I’m very familiar with the earliest learning steps. Even adults are not much better in many instances where they never learned to ride a bike. Coordination and understanding of many systems at once is a challenging mental and physical task at first.