The left in the US and Europe is just a very small portion of politically advanced (arguably) workers and petit bourgeoise - even if we were to all agree on a course of action and a concise set of political values, it would not accomplish anything other than to feed our own egos.
If we want the power to implement our preferred program, we need to be organizing our fellow workers, not arguing online. We need to have real answers to their questions, and have a real platform, so that they would join us.
Honestly, everything else is just lifestyleism. Of course many of us know this but we choose not to organize anyway, either because we feel too impotent or we are afraid of sticking our necks out.
While "go outside and talk to people" is always good advice, the internet is the modern-day public square and superficially silly stuff like memes are modern-day agitprop. To do anything we need to grow the left, to grow the left we need to convince people of our ideas, and the way to convince people of our ideas in a heavily-propagandized and heavily-online world is through creating our own online propaganda. Forums like this do that work, and while that work isn't the whole puzzle, it's at least one necessary piece.
People change their minds based on what they read on the internet all the time -- that needs to work in our favor.
To add to this excellent point: