It depends on the kid. My oldest kid wasn’t able to get the idea at one and a half when he got his strider. At two he had the idea, but wasn’t good enough. At 2 1/2 he got it, and at three he outgrew the strider and needed a bigger balance bike, because he didn’t get pedaling til four.
For the second round we had twins. They got their balance bikes at age 2. The girl got it at about 2 1/2. they are 3 1/3 now. The girl can go around the block and is maybe ready for pedals, except she hasn’t figured out the brakes yet. But the boy is only just getting the balance bike.
some of it is just practice. My first kid got a weekly ride/stroll with the twins in the bob stroller to a donut shop. But the twins did not get that, because we moved to a house that’s too far from the donut shop.