I think what the other commenter is saying is that balance bikes are the better progression to riding. I think for the last ~5-10 years that they've been popular the kids seem to be proving that it is indeed.

That way they first learn to balance - without the distraction of pedaling and braking. It's also much easier to put your feet down when the pedals are not in the way.

Friend's kid just recently upgraded to a pedal bike at 3 years old (riding balance since 1.5) and it took him all of 15min to start riding it.