Yeah, but it's not only about how much you make. It's also about the effort invested.
Content writing will never be a passive income... And honestly, for a really good, 1K word article, counting in research, first draft, reviews, communication with the client, etc, you need to count 3-4 hours, at best! (especially if t is not your niche, and most writers will write just about anything).
Now, do your math: How much would you need to charge per 1K words to make it reasonable source of income for you? If you charge $20, and not many people here would pay that much for 1K words, you're earning $5-6 an hour... + once you stop writing, your income drops to zero immediately...
In my opinion, considering current market prices and everything else, content writing is not a field to dive into. There are many other more profitable niches of IM