Webmention
You post a comment on your own site, and ping a service to let another site know you commented on their site. The comment doesn’t live on an external site.
TLDR: UX needs to be smoother for mass adoption. without adoption this isn’t useful.
PRO
- you own your data
CON
- people without a website can’t comment
- too technical
- still relies on a 3rd party
this article from brainbaking.com says integrating webmentions is too technical, and not worth the effort. Nobody will webmention your page, because it’s not easy & popular.