I know a lot of boys and girls around this age (maybe 20 I see on a regular basis), and we take our trike to the park often with these kids. A fascinating thing that I thought was a coincidence was that NONE of the boys would pedal it. NONE of them. The girls all did from age 2.5 on, but the boys would be up to about 4.5 before they would put their feet on the pedals. Probably that extreme divide was a coincidence, but I think that if the average is three or four, that might be heavily weighted because of girls. Trikes teach steering and pedaling, balance bikes teach balance and steering. Either way you have one skill left when you get to the real bicycle--I think you're fine and can skip whichever one you want, LOL!
 And I agree... it's not like something you NEED, to learn to pedal. It's just for fun. Some people never learn to ski, and that is okay!
Oh, and also... not all children crawl. DD2 didn't crawl. She walked on hands and feet for seven months!