As far as I can see, if things continue like this, I won't have any money from Medium to pay my FOM. Then what are we paying for? What does Medium do with all that money?

Great question!

This is why a lot of writers -- myself included -- have withdrawn from the FOM program.

I'll be gone as of February 11.

I was paying that extra $10 because I believed that $$ would be going to my fellow writers.

Obviously, it's not.