There are probably plenty of right wing instances you're not federated with, but now that mainstream social media has been overtlu taken over by fascists there's not as much reason for it. When I first heard of Lemmy I remember there were a shit ton of far fight instances because that's who was getting kicked off of reddit back then. Now, though, the owner of Twitter is straight up doing seig heils in front of crowds and you can get banned on reddit if you criticize him too much. So if you're a conservative, why would you bother using a weird open source platform like Lemmy when the big dogs are all in complete agreement with your beliefs and all your heroes are on those platforms, especially when your ideology is based on hero worship?

TL;DR if you're a right winger you're just on the mainstream platforms or on an explicitly right wing alternative like Truth Social