Yes, competition.
Any competition. USPSA and IDPA will be the most common for self defense oriented shooters. But get out of your comfort zone. Shoot something different than you do normally. If you regularly practice on your own, then any competition is good. If you usually shoot IDPA, then go shoot some USPSA. Go to a different range where you don't know anybody and you might feel uncomfortable because you are a stranger. If you don't participate in structured competition, then you are doing yourself a disservice. You can't test your skills without a test.
Get out of your comfort zone. Go to a class where you don't know anybody and perform in front of strangers and the famous instructor.
There are other ways to test your skills besides competition. Be the first to post your scores on The Drill of the Week. Does anybody shoot it then not post your scores because you don't think they measure up? Then man up and be first.
My first "competition" was police qualifications in basic training. Next was the bowling pin shoot at Second Chance. All of a sudden I was at a National Championship competition. I didn't do very well. I read an article by Mas Ayoob that said I should shoot regular competition to prevent match nerves. I soon started shooting IPSC and the rest is history. After a while match nerves weren't as much of a problem and I could concentrate on technical skills.
Get out of your comfort zone. In the last 3 years or so, I've started shooting long range 22 rimfire rifle matches. I was out of my comfort zone. Same when I started shooting Cowboy matches a few years ago after shooting mainly USPSA.
If you can't do a competition, then make your own competition with yourself. Start a training journal here and regularly post your scores on standard drills like Dot Torture, Bill Drill, The Test, El Presidente, etc. One of my favorites over the years is the latest DotW, the original IDPA Classifier. https://pistol-forum.com/showthread....DPA-Classifier I have records back to 1998 when I first shot this.
Get the idea? Get out of your comfort zone.