That’s a good point. Age is a big factor in what you start with as well.
If your a kid, you go with what engines are available at your age level. I think if my son starts racing any time, I’d like to start him off with lower HP engines. Two factors – Speed and Maintenance. The slower speed can teach drivers to be smooth instead of all over the wheel like you tend to see with higher HP engines. And the lower HP engines seem to be less maintenance.