I have the same experience. I invest a lot of time in articles and try to add real value and teach something to my readers. People really dig it so far.
I published just one article this month and earned more than your numbers with that one alone. The older articles also keep earning me 5 to 10$ a day so it all adds up.
Tech stuff does well on medium so perhaps it’s easy for me to say. I’ve noticed that it’s much harder to earn serious money with the more generic topics everybody can write about. Productivity, mental health, etcetera. I can image you can only earn decent money if you write a lot and build a good following in those categories.
So I stopped doing that and focus on what works best for me — writing technical stuff that requires research and where I can really add value from my work experience.