I wrote my books for years with rST. (I also used Asciidoc, and one publisher wanted me to use Word.) Recently, I migrated all of my tooling to Markdown.
It turned out that no single markup language supported all of the features required to make physical books, so I would need custom tooling regardless. The rest of the world was moving onto MD, and even though I'm a huge Python fan, rST is painful, and writing tooling with it is even worse. (I also have commit rights for docutils.)
I don't regret my choice one bit. It has made my life much easier, and I can work much faster today.
It turned out that no single markup language supported all of the features required to make physical books, so I would need custom tooling regardless. The rest of the world was moving onto MD, and even though I'm a huge Python fan, rST is painful, and writing tooling with it is even worse. (I also have commit rights for docutils.)
I don't regret my choice one bit. It has made my life much easier, and I can work much faster today.