The claim that "beer goggles" aren't real may or may not be true, but cannot be supported solely by the study referenced within the claim. The study uses a group of 36 same-sex male friends, with 20 of them being white. No women or persons of other identification were included in the study, despite the article by The Guardian generalizing the study's results to all people. The fact that the participants were friends may also lead to similarities in results, and as the pool was predominantly white, it is again difficult to generalize the results to all people. The study does, however, reference the idea that alcohol will give people "liquid courage," which has been supported by other studies.
https://www.jsad.com/doi/abs/10.15288/jsad.22-00355?role=tab&journalCode=jsad
While this study found that alcohol does not seem to affect attractiveness ratings, there are studies which argue that alcohol does increase attractiveness ratings. One of such studies was conducted in 2008 by the Department of Experimental Psychology at the University of Bristol, detailing that 84 male and female participants were tested with male and female facial stimuli immediately following alcohol or placebo consumption, and 24 hours later. The study found that attractiveness ratings were higher in the alcohol group compared to the placebo group, for both same-sex and opposite-sex facial stimuli. These effects were also shown to have lasted 24 hours later in male participants rating opposite-sex faces.
https://pubmed.ncbi.nlm.nih.gov/18684808/
Another study conducted in 2014 at Southwest University in Chongqing, China supports the idea that alcohol lead to increased attractiveness ratings. This study was conducted with 103 male and female participants, randomly assigned to alcohol or placebo groups. Both were asked to assess the attractiveness of both faces and landscapes, with three levels of attractiveness, being high, moderate, and low. The study found that attractiveness ratings for moderate and low-attractiveness faces were significantly higher in the alcohol consumption group than the placebo group, and that high-attractiveness face stayed the same. For landscapes, only low-attractiveness stimuli were rated significantly higher by those who ingested alcohol compared to the placebo group. Researchers concluded that alcohol consumption tends to lead to increased attractiveness ratings for low-attractiveness stimuli, and this effect does extend past faces, but the effects of alcohol consumption on attractiveness ratings depends on the initial attractiveness of the stimuli.
https://pubmed.ncbi.nlm.nih.gov/24858916/
Despite this, there are also studies which, like the one referenced by The Guardian, argue that alcohol does not affect attractiveness ratings with convincing research. Thus, it is difficult to say whether the claim that "beer goggles" aren't real is true or false, and further research must be done.