You might have a bit of confirmation bias going on there because I've seen countless bang average looking guys pulling and dating absolute worldies. (and many decent looking guys settling for average girls). Everyone says it so often but personality really is just as important as looks, especially if you want longevity (FWB, girlfriend).
Obviously looks are incredibly important, it gets you into the door. Everyone tries to pull attractive people. However attractiveness is incredibly subjective, one person's 6 is another person's 9. So even if you're a '3', there can be a 7 who thinks you're 6 and therefore attractive enough for them. Your best bet is to improve yourself and maximise your other traits that people might like. (Personality, Physique, Hobbies etc.) Level Up.
Make-up plays a huge role as well, a lot of these stunning girls aren't all that amazing without the fake tan and concealer. So while you hold them up as the pinnacle of beauty, they're just average, normal people. If you go in with a self-defeating attitude of "I'm not good enough" you'll just end up with a self fulfilling prophecy.
You might as well try, you never know if that hot girl will think you're the most good looking, funny guy in the world.