It doesn't prevent phishing attacks, though. Popular bitcoin mixers have had scammers go after cloning their onion links as well. Just check this thread and you will see a number of reported copycat onion links
1. https://bitcointalk.org/index.php?topic=5381839
It's funny, but I don't see a single phishing site similar to Mixy. I guess this is not very good news (in the sense that it just means that Mixy does not seem to be very popular among mixers, so it is probably not profitable for scammers to engage in phishing). Although maybe I'm wrong. 1. https://bitcointalk.org/index.php?topic=5381839
A clearnet domain with only 4 letters is quite expensive. On Namecheap, mixy.net is available for $10k and mixy.io is $6k. There are cheaper options but I doubt anybody would fall for a fake mixer with a .beauty or .monster domain name.