So, what do you really think, Captain Obvious? LOL. Of course, you're right. In the areas of Reddit and Quora I hang out, contributors produce quality or sink to the bottom. The communities there are rough on people who pollute the space with no-value posts. Since half the people on the trending page here can barely write in English, it's fair to assume their fans can't read in English either.
Still, there are some good curation efforts, so some of us just contribute when we feel like it and let the digital chips fall as they might. When I want to make sure I can get paid to write, I work for clients with credit cards.
Writing skill has a rough correlation with payouts amongst early adopters, but it's mostly about money recognizing money and people voting on each other as such.