I know there are many still actively using Microformats. Sometimes the wiki can have older examples and there’s always linkrot. On hCard (microformats v1), you’re probably better off looking at the newer h-card (v2) specification and examples. In skimming it tonight I notice that Mastodon isn’t listed on the page though they support it. My own site parses them to pull in author names, URLs, and avatars in the reply contexts on my posts.
I recently found https://indiewebify.me/ good in testing and fixing an h-card I set up on one of my wikis/digital gardens.