You’re likely setting your standards above what you’re batting at.

People love to say this. "You're a 5 trying for 10s. Get real."

That's not the situation here. Most women that people fawn over don't really do it for me. I prefer the type that most people would overlook. The more plain or mousey look that people seem indifferent to is what I'm generally most attracted to, instead.

Confidence also doesn't really come into play with online dating. Your picture is what gets you attention the vast majority of that time. Pictures of an attractive person with an empty profile or a profile that shows an abrasive personality will get far, far more attention than average to unfortunate looks with a profile that has tons of personality. There have been many experiments that show exactly this.

Confidence only works when someone decides to give you a moment to let that shine. If you get ignored than who you are, one way or the other, will never matter.

You're right that confidence and whatnot can help. But it can only help so much and some people have too far of a gap to make up. Some people are doomed to only find company in the situation where neither is really attracted to the other but someone at all has become the more appealing option than continuing to have no one at all.