I use Ghost for a while now and it's fantastic. The fact that it's open-source, self-hostable, super customizable (themes), has free/premium memberships and can be used both as a blog and newsletter is what makes me stick to it.
Ghost is $9/month to start, even if only your mom is reading it to start. (And you don't get customisable themes at that tier.)
Not hard to see why one is much more popular than the other.
People just want to write their article and have it come up at the top of Google search results, that's the hype.