I think this question could be looked at another way: Is it helpful to be good-looking?
I think there's pretty much no doubt that it is. Humans respond well to things that give them aesthetic pleasure, whether it's a beautiful vista, an attractive person or a well-designed product (see: Apple). Impressive-looking people are definitely favoured over less impressive-looking people; study after study confirms it.
Whether this should be so is kind of irrelevant to me from an external perspective; there's plenty of evidence that is just is. From an internal perspective, I just try to stay mindful of the natural prejudice towards beauty, because it opens me up to a wider range of experience if I fight instinctive biases.
However, I honestly believe it's much less about the material you're given than how you work with it. If you're not naturally attractive but you want to be treated favourably, extremely good grooming/presentation can compensate for/significantly improve a lack of natural looks to the point where you're not disadvantaged at all, and can even have an advantage over good-looking slobs. If you dress better than 90 percent of people around you, if you have a sharp hairstyle, if you put together outfits well and have a strong personal sense of style, if you appear to take good care of yourself and be in good health, people will respond to you pretty much as favourably as they would a naturally beautiful person.
It's responding to the same aesthetic preference as for natural beauty, but it's controllable, and therefore empowering.