Antifa arose in 1930s Germany as a competitor to the other socialists, the Nazis, who also had a paramilitary faction and used violence and intimidation against people. In the rivalry between Antifa and Nazi in Germany, however, the Nazis won out and now barely exist.
It should not be surprising that Antifa uses the same tactics as the Nazis. They were competing for the same followers.
As an aside: Soros ... the guy we aren’t supposed to believe was a Nazi is behind this bunch ... also something we aren’t supposed to believe.