The problem is that there is nothing that can replace rst currently. The reason Sphinx uses rst is because it's incredibly expressive and extensible. This is

The problem is that there is nothing that can replace rst currently. The reason Sphinx uses rst is because it's incredibly expressive and extensible. This is incredible important if you want to write good documentation. For instance you can use `.. versionadded:: 0.2` to indicate that something was added in a specific version. The builder then render a nice and consistent block that can be styled in whatever way necessary. You can use :ref:`bar` to reference something in Sphinx, :kbd:`alt + k` to indicate a key sequence etc. We could not have used Markdown for this without making a new dialect of Markdown. Also unlike rst Markdown is very ambiguous and restrictive. There are certain elements you can't use below others. That very, very rarely applies to rst. For instance you can without a problem have code blocks in tables or code lists in tables etc.