I've been on here a while and learnt a lot about earnings. It's tough. It's possible to earn big on here but you have to be prepared to write thousands of articles. And you have to end up more of a production line than a craftsperson. I don't want to be THAT person that plugs their own articles in the comments section of others, but you might be interested in these:

https://andytaylorcardiff.medium.com/theres-no-secret-to-going-viral-on-medium-2eb0d89f7edc

https://medium.com/3-great-reads-about/3-great-insights-about-medium-9405434151df