It's not your writing.

It's that there are many more writers on the platform than there used to be but the pot from which payments to writers are made hasn't grown at the same rate.

So, where my work used to reach 500 readers a day and earn $500/month, now it reaches 100 readers a day and earns $80/month.

And as a result, I publish my original work here less and less often, which leads to even fewer readers and money made.

There are people who make good money writing on Medium but I'm not one of them.