As usual people - read past the headlines.
First - yes, I believe that most, less-attractive people think (hope?) they are more attractive than they are.
Second - this study seems like nonsense in it's execution.
In the first study (of two)?
The total group of people who decided how attractive the subjects were?
Were two dudes.
That's it...just two guys!
Calling that a 'fair study' is beyond ridiculous.
The second study - apparently - used four women and four men to judge 'how attractive' the respondents were.
And though that is far better than the first, joke of a study.
It's still an incredibly, small number of people to come to a conclusion about ALL humans on the entire planet.
In addition.
The respondents (the people being judged) averaged (mean) 33.8 years of age.
That could be important.
If the 'judges' were all of university age?
Which - given that the second study was done at a university, is possible. If not probable.
That means you have - potentially - college-aged students, judging the looks of people, MUCH older then themselves.
Obviously, an 18 year old guy is going to be more attracted to an average 18 year old gal than an average, 40 year old gal.
The whole 'report' seems like nonsense to me.
https://onlinelibrary.wiley.com/doi/full/10.1111/sjop.12631