Limit what you see. I've seen a lot of people complain about how they don't like Battle Royal games (I personally like them). I personally don't like Horror type games. I'm sure I'm not alone with people having opinions about various genres.
Allow an option on your account to select what type of games you see. If you don't want to see Battle Royal games, you select no battle royal games seen. As well as any others.
I know this can limit an audience greatly from a business stand point, but giving the viewer more options about what they want to see is similar to what Netflix, or many other streaming platforms, do.
This can also provide valuable data to Mixer as they can see where a lot of their viewers (who are willing and able to dive into their settings) want to see, or are most interested in for a stream; inversely what they are LEAST interested in as well.
Ti Butler commented
I think this is probably better implemented as part of a Search feature, like this one: https://watchmixer.uservoice.com/forums/382521-mixer-feedback-ideas/suggestions/37434664-search
Buster The Fox commented
A HUGE +1 from me! Right now, Mixer kind of feels like "the battle royale site", as far as what I'm presented with on the home page. As someone who's just not that into the whole BR craze, I would find the site a lot more enjoyable if it were tailored more toward my preferences (Plus, giving partners a reason to stream literally anything other than Apex or Fortnite).