I'm also reasonably sure other factors also influence these algorithms. Hair style, framing, lighting, the clothes found on your shoulders, angle, distortion by the camera lens, and most importantly, similarity to high-scoring faces in the source data set.
My self-esteem is fine! A 5 is not bad : half of people are prettier than me, half are less pretty. But calling a "5" a "1" is a little mean, no? ;-) Don't really care.
Sorry to break it to you, but I'm pretty sure the wording on the site (which I don't have open anymore) suggested 5 was below the "normal" range, which presumably means it's well below the median. I'd be extremely happy to hear some more flattering interpretation.
Then you're missing the point the website makes about this and other algorithms like it being extremely unreliable. There are tons of biases in the training data, and not just ethnic/cultural ones mentioned. For starters, you're comparing a crappy webcam to a model that in all likelihood is based on people's best selfies.
The model tries to fit you into a very narrow niche. On top of that it will do so poorly.