I started shooting photographs of birds for a very simple reason. Birds are extremely hard to photograph well. For one thing, they are generally quite uncooperative on their best days and generally hopeless on their worst. And I have thousands of crappy bird photographs to prove it.
But, while practice doesn't necessarily make perfect (only perfect practice can do that), repetition does have a way of solidifying muscle memory, and teaching your muscles to memorize the right moves is a step in the right direction. Back to the notion that birds are hard to photograph; I reasoned that, if I can reach a point where I can reliably photograph birds well, I should be able to photograph almost anything without shaking the camera and screwing up the pictures.
I have thousands of crappy bird photos, yes, and I keep them to keep me humble. Because eventually, through constant repetition, I have acquired quite a few very good bird photos. If I tossed all of the bad bird pics and only kept all of the good bird pics, I, might delude myself into thinking I came by it naturally.
Shooting birds helped prepare me for those times when being steady really counts. Like shooting football and basketball.