The space isn't saturated, but there is some competition. However the quality is often lacking. I maintain a smaller set of high quality articles, and keep those updated. I also have a more simple, direct writing style, and designed the website for readability.
I considered expanding to other places or bringing other people on board, but I doubt I could maintain the same level of quality. Those articles require far more research and domain-specific knowledge than your typical SEO spam.
I'm also not that interested in growing. I want more time, not more disposable income. I am sitting on a few decent business ideas, and this website could easily grow to cover other countries, but I'd rather do more pleasant things.
> How much do you earn
About the same as I did as a developer, though it's hard to get a precise number since it varies a lot.