At this point I considered myself a pretty good shooter, humble but competent.
I decided to go shoot a USPSA match and promptly discovered what I didn’t know about shooting.This mirrors my own experience in a way. While my exposure to competitive shooters wasn't at a match but at a class, it was pretty much the same sort of deal. I saw someone who was an exceptionally good shooter because of their involvement in competition and it opened my eye's to what being good at shooting a gun really looks like. I can now trace most of my skill development back to that moment.
It is important for people who take defensive shooting seriously to expose themselves to competitive shooting not just because of the competition aspect like a lot of people say, but because of the pure skill some of the other competitors have. Seeing that skill in person, and having a direct comparison to your own skill by shooting the same stage or same drill in my experience is a huge motivator to improve because it shows us where we actually are with our skill level and what is possible.