Tribalism remains deeply ingrained in our psyche because we're biologically not much different than the hairless apes that roamed the African continent hundreds of thousands of years ago. What has changed is our culture and our societal views, what we consider part of "our tribe" and what we consider "others". In that sense we have changed a lot in the last few centuries. Just a few hundred years ago slavery was considered acceptable and women were treated like property of men, the mere thought of treating them like human beings was considered ludicrous.
It is an uphill battle. We have a biological tendency of wanting to picking sides and psychological biases that make us see those on "our side" in a positive light and those in the "other side" negatively. It's not only biological factors like sex or race, it's also political ideology, economic status, nationality and many others. They're all factors that help us separate "us" from "them".
I'd like to say "we can solve this by doing this and that", but the truth is that there's no easy solution. The Internet has helped with radicalization and furthering division. Riling up people gets clicks. Creating echo chambers with high levels of engagement also generates clicks and thus ad revenue. The current overlords of the Internet thrive on controversy. I guess the only positive action left would be to avoid falling in the trap of pointless tribalism and encourage others to do the same, but to be quite frank I'm not exactly optimistic about the future.
