To answer the question in the title: absolutely not. Beauty is relative. What appears to be beautiful to us might be ugly to others and as you’ve mentioned, there are also a lot of variables at play. A beautiful person with ugly personality will look ugly.
No one says it better than Roald Dahl in my opinion:
“A person who has good thoughts cannot ever be ugly. You can have a wonky nose and a crooked mouth and a double chin and stick-out teeth, but if you have good thoughts they will shine out of your face like sunbeams and you will always look lovely.”
I love this post! Thank you for reminding me the true meaning of beauty!