Here's what I've noticed about myself and with others growing up with Taekwondo. Winning is often rare in the beginning. And red belt is still pretty much beginner level, although you probably think of it as advanced. But over time, all the training, the skill, the physical abilities, the way someone moves, their emotional and mental maturity, everything will come together. And when that starts happening, you're going to notice more and more wins in competition.
That's just part of the process. You'd like maybe a taste of winning every now and then until then. But sometimes that just doesn't happen, despite working so hard. It can wear you down and make you think this isn't for you. I get it.
But like I said, everything comes together at some point for everyone so long as they keep at it. For some it occurs sooner than for others.
There's a reason for everything. When someone isn't winning at all, there's a reason for that. It may not be that the person isn't training hard enough, or isn't serious enough. Someone just might not have something figured out yet. Or, maybe there's just one small detail that's making all of the difference.
Often times, someone may be technically better skilled, but the win will go to the competitor who merely "looked" better doing it. Judges are definitely biased and can be fooled. No doubt about it.
Sometimes people need to stop and ask an instructor what do they see that the student needs to work on. And if that instructor can't tell you, go to another one and ask. Get lots of eyes looking at you, and you'll hear some good, constructive criticism. A red belt is going to get lots of criticism.
Here's another thing to realize. Child divisions in Taekwondo tournaments sometimes combine red belts with black belts and brown belts. Together, they make up an "advanced" division. The black belts will generally win more often. It seems unfair. But that's how divisions work. Even if black belts are not included, it's still brown and red belts together. And so the red belts should generally win more often than the brown belts. Which explains why you might not have won when you were a brown belt. And maybe you're really new in your red belt, so it's like being a brown belt still. You might not win until you're almost at black belt level.
So I'll say it again. Just keep at it in earnest. Ask for critical feedback. Record video and play it back to see your problems. Work on physical attributes, too (speed, strength, sharpness, focus, timing, etc.). Eventually, things will come together. The wins will start happening.
Hope that helps.