why do you think that is?
Just spitballling here, but maybe it is because more reliable information is on X, Sure, someone may say something stupid and/or untrue, but there will be MANY who have a surprising depth acknowledge on that subject to correct the poster. It really is a self-correcting system.
Truth is found in opposing arguments. And the Left avoiding such arguments eventually renders them unable to defend their positions. Their ability to argue is now all for decoration, and not for actual use. It has become little more than a vestigial tail for them.