“Training Wheels” are generally called “Stabilizers” outside the US. They exist and people use them.
Balance bikes also exist in the US and have for just as long as they have existed in Europe.
But this is not about either. A real bike without pedals is needed, because the transition from gliding to riding can take as little as 30 minutes. I mean, for sure, get your small child a balance bike and let them use it for fun. In my opinion, a razor scooter-type thing is even better. The key is to get the child to not worry about being slightly off-balance and instead of panicking they steer and/or lean to correct.
Years ago, I paid REI $50 for a learn-to-ride class for my oldest son. They did this remove-the-pedals thing for 100 kids in a group and had every single one of them riding in an hour with just 5 or 10 instructors. I watched the whole thing in amazement and did it on my own with each of my younger kids. It turns out that it is really easy to teach, and my youngest was riding a real bike at age 4.
> In my opinion, a razor scooter-type thing is even better.
I'm 44 and still can't ride a two-wheeled scooter. I don't know if it's harder or different from bicycles (which I have ridden regularly and enthusiastically since I was about 7), but it just won't click for me.
Not sure what I wrote that upset people so much. Do whatever works for you and/or your kids. I apologize for suggesting that there are multiple approaches to solving this problem.
Looking back, perhaps I was offensive for suggesting that Europe and America were pretty much the same on the topic of learning to ride a bicycle. If that was the issue, I do not apologize.
It isn't universal in the US. I had never heard of balance bikes until this thread. All my friends rode tricycles as toddlers then bikes with training wheels gradually adjusted higher until they were removed.