It is not uncommon for individuals and even entire organizations to rely on some third party platform to host all their thought-leadering. Medium is the common choice, but many use other platforms as well, such as LinkedIn.
While many argue that the reach is better and it is easier than self-hosting, few consider what will happen when their chosen platform goes away (or the platform chooses to purge you). After all, the web is littered with the corpses of platforms populated by content that you wrote and that we will never see again.