These are all fantastic things that are built on top of Webmention but that I often feel are conflated with Webmention.

I'm in the middle of (ahem) adding Webmention support to this site, so I found this take on some of the many things that can mean by Marty pretty interesting, particularly as someone who (on first glance) envisioned a bold-new, Webmention-driven world and rapidly discovered it's a lot more nuanced than all that. His conclusion, though, feels like a particularly useful frame of reference when thinking about the technology:

Maybe Webmention can be thought of as less of a "building block" and more like a glue. You can do so many things with glue, like combining a bunch of planks into a table, or building a parade float sculpture with papier-mâché, or doctoring the photo in a passport!

You wouldn't call them all "glue".