Are good looks an indicator of strong genes?

Something I've been thinking about a lot lately, is why are good looks, good looks? Like is there a reason certain features are attractive, and others aren't? Why are our brains wired like this? So I did some research, and I found that it's not the looks themselves we like, but rather what they indicate. So, what do good looks indicate? Everything happens for a reason, humans don't just decide, this looks good just because it does. Like what do certain features indicate, for example, a strong jawline or something like that.