The anarchist symbol has been used by tons of groups, both left and right, throughout history. You can find it almost anywhere that has a substantial amount of graffiti and I'd bet more often than not it's just done by kids/teens that have no significant group or political affiliation. The video doesn't even show who sprayed it and basically everyone looks like your average teen. Labelling this as "Antifa" because someone spray painted an anarchist symbol and someone has green hair is a bit of a stretch.

What group, other than anarchists, uses that symbol in 2020?

It probably was sprayed by teenagers, but by spraying it, they're indicating their political affiliation.

In addition to what sdkjfhskjfh says, Antifa is not exclusively (or even primarily) anarchists. I've met quite a number of people who participate in Antifa counter-protests who are not anarchists at all.

It's like "libertarian" or "feminist". It's a label you can use to describe a stance or general association with an idea, but not much more.

Being "anti-fascist" can mean a lot of things to a lot of people, but using the "antifa" label makes it sound scary or organized. It reminds me of media outlets talking about message board trolls and disruptors as "the shadowy group known as Anonymous".