I think the main issue with microformats is most CMSes don't really have a good way of adding them. You need a very capable rich editor to add semantic data inline or edit the output HTML by hand. Simple markup like WikiText and Markdown don't support microformat annotation.

JSON-LD in a page's header is much easier for a CMS to present to the page author for editing. It can be a form in the editing UI. Wordpress et al have SEO plugins that make editing the JSON-LD data pretty straightforward.