It has been scientifically observed and proven that those who are good looking receive benefit from it in a variety of ways. However, I do want to qualify that with two points.
First, the extent to which a person is attractive is hugely subjective, and there are relatively few people that are objectively extremely attractive. There has, again, been scientific testing on this (there was a recent Times The Story podcast on it which was interesting) and as part of that it did attempt to define how 'attractive' individuals are. Invariably, most people fall into the middle range, and very few are at the very high or low range. But beyond that, there are a lot of teenagers and others on this forum who bemoan the fact that they are not attractive, but what they miss is that there are so many things that individuals can do to make themselves more attractive. Working out and actually altering your physique is one, but there are so many more. Getting your hair cut properly. Getting clothes that suit you and actually fit properly. You'll feel better doing those things as well, which will boost your self esteem and make you more confident as a result. So for people reading this thread and feeling down about the attractive people who are getting all the dates, forget them and focus on yourself. Be kinder to yourself, and do things to boost yourself. It's amazing how relatively small things can make massive differences in this respect.
Second, as much as being attractive is an advantage, any given situation, be it trying to get a date with someone, getting a job, or whatever else, have so many variables involved that you cannot point to one thing that has definitively caused any given outcome. People and situations are complex, and distilling them down to one factor is neither accurate nor helpful. And again, it particularly isn't in a situation where you're down about your own perceived attractiveness and comparing yourself to others. That isn't only extremely unhelpful, but it is also right. You're comparing one or two aspects of someone else's life to the many more complex aspects of your own. That is just not the right way to do it. You might be able to highlight someone as attractive, but you have no idea what other difficulties they're dealing with, or positives that they have, because people largely don't make other people aware of those. In a book I read recently it was suggested that people "drop comparing their insides to other people's outsides", and I think that's a really good way of putting it. Just stop making these comparisons and focus on your own wellbeing.