I wonder if this might be due to the fact that most fighters will train against right-handed fighters so left-handed fighters might be less predictable and thus

I wonder if this might be due to the fact that most fighters will train against right-handed fighters so left-handed fighters might be less predictable and thus have a higher win-rate. This will cause them to be more successful, and more successful fighters are more likely to stay in the sport and thus this leads to them becoming overrepresented.