Probably the Facebook effect: you subscribe to communities you feel close to, and your picture of the world gets entirely warbled.
Don't like r/guns? There's r/socialistsgunowners for you. Have a problem with r/army? We'll gather at r/leftistveteran (names probably approximates, I haven't been there a while)
In my 10+ years of experience on reddit using RIF, even r/texas would only show up on the front page around horrible stories of LGBTQ rights denials, or tragic anti-abortion laws being put in use. Made me think the world was full of human beings I could relate to.
An algorithm is just that, a method to get you to keep seeing the ads for as long as possible. In a way, reddit allowed you to stay in your "reasonable" zone easier than FB or, worst of all, YT, which doesn't have the "Community" boundaries. With RiF I was able to filter out gossip newspaper, everything YT, some triggering keywords... You could make it what you wanted. As delusional as can be.