He's the boogey man to a large portion of society. He makes the left look slightly bad so any chance to showcase he's just an evil capitalist that steals grandmas money rockets to the top of HN.
Russia doesn't like him because he has been active in encouraging Ukraine's adhesion to the West. The amount of Soros Bad narrative since then (2015) has increased a lot.
But he isn't really of "the left", he has mainly funded centrist Democrats, not the progressive wing; as you say, he is a capitalist. And his influence is greatly exaggerated.
100% agree, doesn't change what the right believes he is though.