The problem with anti-semitic conspiracy theories is that they involve continuous selection. Therefore, you take the fact that Karl Marx was a socialist, and overlook that he was a racist and cultural conservative. You take the fact that Mahler was a musical revolutionary, and overlook that he was a German nationalist. You wholly overlook people like Ayn Rand and Ludwig von Mises, or Paul Gottfried and Meyer Schiller. You also overlook how many poisonous lefties there seem to be in Israel, calling for open borders and the demotion of Jewish symbols. Jews tend to be opinionated and vociferous.
There are Jews arguing fluently on each side of every argument. You can put together a very convincing theory of Jewish subversion by selecting certain opinions of certain Jews, and ascribing these to all or most Jews. You are left with a composite Jew that may exist in a few instances, but is not representative of the Jews we meet in our everyday lives. You could, by using the same method, but applying a different principle of selection, prove that Jews were sexually-repressed white nationalists with a tendency to convert to Roman Catholicism. You will also find examples of the resulting composite. Again, it will be unrepresentative.
The truth is that we’ve messed our civilization up by ourselves, and would have got where we now are even if every Jew in the world had fallen dead c1870.