There are three reasons I wanted a blog of my own, and none of them is reach.
a place to finish thoughts
Notes apps are where ideas go to die. They're too private to be accountable and too cheap to be edited. A blog post, even an unread one, has the one virtue that a note doesn't: it has to end. You have to decide what the argument is.
ownership
Posts written on someone else's platform belong to them. The URL can break, the styling can change, the whole service can vanish. A static site on a personal domain is the simplest long-lived option — no database, no framework churn, nothing to migrate in five years when I've forgotten the password.
slower pace
Plain HTML is slow to publish, which is part of the point. The friction is the feature; it discourages half-formed takes.
If the site sits mostly empty for a while, that's fine. It's the finishing habit I'm after, not the volume.