HTML requires a huge browser binary though, and the JS library should be cached on first visit to a page that uses it. Seems the right trade off to me to have a one off download for this use case (i.e. potentially viewing many pages on the same site, as opposed to a small number of pre rendered pages) then only need to transfer plain text which is already in the markdown source (so is needed if you’re going to edit or view the raw MD anyway).