I learned that it is pretty easy to do a wheelie. I learned that the difference between a beginning rider and an expert rider is a beginning rider needs a kickstand. An expert doesn't need a kickstand. The kickstand adds more weight. Experts can also go on harder tracks.
Different bikes have different parts for what they are used for.
Some bikes just don't need them. It would just add more weight. BMX bikes need pegs for some of the tricks they do. I learned that crome bikes cost more than a color bike. They cost more because the crome doesn't rust plus the actual crome costs more.