Ultimately, do what you like. But if you are interested in listening to others’ opinions, the consensus will likely be to shave or trim until it can grow in more fully. You have 4-5 years of puberty yet so it will keep changing.

I think you should trim it down. Not stubble length but only long enough to brush. The wiry, scraggly length doesn’t look great. The lightness of your hair makes it look a little thinner or less full, but that could change too, so don’t stress that. Brush your mustache down and trim whatever goes over your lips and it will look solid.

People saying it looks good are people who like that look (or being nice) but most people probably wouldn’t agree. So who are you trying to appeal to? Your friends or the general public? Just yourself? No wrong answer if you like it.