Medium is a platform for writers and readers to share and consume content. While it is true that Medium earns revenue through its Partner Program, where writers can earn money based on the engagement their articles receive, it is not accurate to say that writers are working for Medium for free.

Writers have the option to join the Partner Program and earn money for their writing based on the engagement it receives, or they can simply use Medium as a platform to share their writing with a wider audience. In either case, Medium provides a valuable service by hosting and promoting the content.

Additionally, it's worth noting that Medium's revenue model is not unique to them. Many websites and platforms earn revenue through advertising or other means, and writers often rely on these platforms to reach a larger audience than they would be able to on their own. Ultimately, the decision to use a platform like Medium is up to the individual writer, and they can choose whether or not to participate in the Partner Program based on their own goals and priorities.