Part of that is a lot of us have a conscious. The right traditionally doesn't have one or a strong one.

You understand that propaganda costs money (and by extension, a person's time), right?

The right has all the money, the left has none. The right has the backing of big media empires, the left has none. A lot of us on the left are too busy just trying to survive in this capitalistic hellscape, and even we did make some "counter-propaganda" as you say, it certainly won't be picked up by the media and/or it won't be taken seriously by an already brainwashed audience.

DNC holds the funds to do the real mainstream advertising campaigns and anyone farther to the left is left with internet memes. Well, mainstream media is being viewed with less and less trust everyday.

Because explaining the cause and effect of a real problem is much harder than pointing to an out group and saying "everyone that's not you is a bag guy"

Propaganda works because it creates enemies. When the real problem is more complicated, it takes a lot more work to explain.

Even if your message is "billionaires are bad" that's a group that people think they want to be a member of, which makes it hard to get behind.

It's much easier to point to people without power and say "you don't want to be them, you don't want to be around them, let's get rid of them"

Because brainwashing is immoral, but it still might be required at this point.