Well, it isn't where I live. Kids from about 1-3 years old get these little 'walker bikes' that have no sidewheels or anything (no chain or pedals either), they use those to learn balance, then after that they get their first bike (age 3 and up) which they usually can ride on right away. By the time they go to grade school they can cycle with the best of them.
Learning how to cycle at a much later age is far harder.
Yeah, that's what I know if as a balance bike. Once mastered moving to a pedal bike is much easier because you've done the balance bit.
We did that bit by removing the pedals and lowering the seat. Once they can cruise then stick the pedals on, adjust the seat, and they're away ... but that's not just "getting on a bike", that's a progression of training.
The thread parent said "never picked up a bike", you transmuted that to "used a training bike and then picked up a full one".
Not pertinent to the thread but the flaw in this technique (balance bike) with my kids has been they learn to brake with their feet and that instinct is hard to break.
While the plural of anecdote is not evidence, I may as well pitch mine in: I hit practically every parked car in the neighborhood trying to learn how to ride my bicycle. So the original point rings pretty true for me.
Riding a bike is probably easier than driving a car but if you never ridden a bike you’re not likely to just be able to pick one up and go with it.