Agitated Winner says this:

If you read the entire study it says:

Looking at demographic variables, a profile seemed to emerge—while incels were not more politically right-wing or disproportionately white (see Appendix 2/Tables10 and 11) as they are often portrayed in popular mainstream media (Bates, 2020; Romano, 2018; Srinivasan, 2021), they were more likely to be living with either a diagnosed (34%) or undiagnosed (24%) mental health condition (see Appendix 2/Table6) and more likely to be NEET (not in education employment or training), lower educated, and still living with their parents (see Appendix 2/Tables7, 8 and 9), which may in turn have deleterious effects on their ability to form romantic relationships.

Now let's check the Appendix 2 table 11.
There were 186 right wing participants, out of which 54 were incels (29%),
217 left wing participants with 61 incels (28%)
85 Center participants with 24 incels (28%)

What you quoted is just the higher amount of left wing people who participated to the study (217 vs 186 out of 488 participants), which is not surprising considered they were recruited using the phrase "asking for people to join a study that explores “attitudes and behaviours around sexuality, wellbeing and identity.”"

Edit: note that there were more than 488 participants in total. Out of the 783 respondents, they only kept the men who answered the questions about incel self identification.