I've been wanting to migrate my (self-hosted) WordPress sites to something that generates static pages (based off of my own templates). I likely won't ever do it, though, simply due to the time required to convert the hundreds of posts/articles I've previously written.

IIRC, Medium has an API which should make moving to a different platform easier, should one choose to do that in the future. One would certainly feel less "locked in" and be more willing to try such a platform if the cost of moving was so low.