Originally Antifa were a pretty specific organization and not just a loose term for anti-fascists in general,
they were a new streetfighting wing for the Communist Party of Germany (or KPD). This would be the same KPD that
already tried a Bolshevik-style revolution in Germany before and
literally worked with Hitler against the Weimar democrats for a while not because the latter enabled horrific degeneracy such as a deluge of child prostitution on the streets of Berlin, but because they were designated 'social fascists' by Stalin (to whom the KPD leadership were enthusiastic servants) and a greater enemy to the revolution than the more populistic Nazis at the time. Antifa's own degeneracy and extreme street violence (as well as that of its predecessor organization, the Rotfront, both against the Nazi SA and defenders of democracy such as the
Reichsbanner Black-Red-Gold) directly contributed to the Nazis' rise to power in the first place, as well, as it made the German people willing to put up with Hitler as long as he annihilated the far-left thugs destroying their shops and assaulting their families and attacking them at their homes every other day.
Current Year Antifa are just following the proud traditions of the original Antifa. Ever seen one of Andy Ngo's 'faces of Antifa' exposes? The obvious drug addicts are the best and noblest of the bunch, more often you're dealing with criminals of various sorts like the three people Kyle Rittenhouse shot after they attacked him (a pedophile, a domestic abuser and a burglar in that order), the guy who stalked & murdered a Patriot Prayer member and was later thankfully brought to justice by the US Marshals, or the Something Awful poster who was recently arrested for shooting a Samoan Proud Boy
after escaping a (firearms-less) brawl. Also like OG Antifa, the modern day ones are certainly no friends to anyone to the right of Mao Zedong regardless of how non-authoritarian they might be and
'liberals get the bullet too' is one of their mottos.
Stalin and Thalmann would be proud: as before, they're a riotous streetfighting horde comprised primarily if not entirely of the scum of society with no hope, no future, and nothing inside their shriveled-up hearts but a sadistic impulse to indulge in all manner of depravity & attack other people on the slightest of pretexts while feeling self-righteous about it. Because of that they can also be easily controlled and directed against the public enemy du jour by the people holding their purse strings, who incidentally also almost always cover for their criminal activity through corrupt local DAs and mayors.