As a male, it seems guaranteed (probably due to supply vs demand disparity?) that you will only have matches that are significantly less attractive than you. I think most people will consider me average in looks. I don't think I've ever matched with a girl that was average on online dating in the 5 years I tried it. I also got professional photo help and put a lot of effort into it etc. As another commenter mentioned, more than half the women I met up with also had an STI.
There has been some research done on the attraction thing, and it has been shown that if women don't know you, they are exceedingly likely to rate men as mostly ugly. If they do know you, however, their ratings are more of a bell curve. So if you want the most attractive possible match (for you), and have the best chance at someone you have the most chemistry with, I think you have to just meet a lot of women in person and get to know them first. It is unfortunate because people are seemingly less social nowadays? So it is kind of a problem that makes itself worse.