Right now I like the #indieweb #webmentions / #microformats more than #activitypub / #jsonld, because the author chooses which replies appear below their post. I think it would be better if there was an expectation to regularly validate the webmentions (we have HTTP caching for that), and also for #xhtml instead of html. I’m not familiar with the LD markup languages, but maybe there exists something more interoperable than microformats (with proper URIs for properties).