Recently somebody me that they thought about putting up a blog, but they "weren't interesting enough."
Interesting enough for what? You don't have to be interesting to put up a blog. The internet won't shut it down if it's too boring.
I have a friend who didn't do sports in high school because they weren't very good.
How good is "very good"? You don't have to be very good, or even "good" to do sports. In Jr High, I was a 5'5 120 lb. weenie, and I decided I wanted to throw the Javelin. Spoiler alert: I never even got close to varsity.
There are no thresholds of qualification for these activities except the thresholds in our minds. Whenever I start something new, I'm inevitably bad at it. I used to think that I was just uniquely bad at things, but I started realizing that's not true. Everybody's bad at new things. It's just that most people discover that truth and then opt out.
If you're letting the opinions of others determine how you should live your life, then regain control and do something your bad at. I don't keep a blog for readers. If I did, I would have stopped a long time ago. I do it because it's good for me.
That's the right reason to do everything.