What about left wing ideology that promotes rioting in disenfranchised areas, and the apologism for it if the rioters are "the oppressed", like POC? I'm thinking about Kenosha right now. Yes, a controversial moment to be sure, but it did demonstrate a double standard in how it was covered. Massive property damage with little support from law enforcement (until later), in the mean time a lot of "white people" were just defending themselves and their properties from mobs. When was the last time you saw right wingers rioting and then apologizing for it with their ideology? That ideology comes from the colleges. So I would say that the social justice politics and critical race theory in the higher institutions definitely has a negative impact on society. Accompanying that is cancel culture, mass censorship (see Twitter), doxxing, altering the education system to indoctrinate, etc. These things are real.
I don't think it's harmless at all. The ideology becomes weaponized when they espouse that the oppressed aren't committing violence against oppressors when they destroy towns etc... it's the oppressed trying to equalize systemic oppression, etc. I am paraphrasing, but that is essentially it.
Perhaps because you are liberal you only see extremism as a right wing problem. I'm moderate/centrist and I see both sides doing highly problematic things right now, more so the left in terms of sheer damage that can be measured in $$$. However, to balance this out, the right wing's damage is ideological when it comes to enabling other kinds of violence, such as rampant pro-gun culture that leads to schools being shot up, and the apologism around that. Maybe the damage can't be measured in $ so much, but its impact on the young generation is massive. They fight against inclusivity and see agendas everywhere when anyone simply disagrees. And yes Trumpists in the capitol... a scary moment to be sure. Controversial though as it seems like the security situation enabled it, which may have right wing implications as well.
In the past 5 years though? The left have definitely become out of control. If you can think of comparable right wing examples I'd love to hear them. I'd like to emphasize, I am saying that both are a problem, but the left is more, currently.