People with extreme views are also more vocal, so that's what you see. That's why social media is bad for you. If gives you a very distorted view of the world. Most people are able to look at politics with nuance.
This, plus everyone is concerned with engagement. If I say a perfectly normal statement on Facebook or X or whatever, no one will care so no one will comment or interact with it. If I say that Jesus wants us to make America white again, even the people who disagree with me will only be boosting my message by commenting.
This is so true, I had a phase in my life where basically all my political social interactions were reading other people's takes on reddit. After a while I found a job and after getting to know people there I realized how insane the takes on political stuff in internet are.