I'm pretty sure there are tools that allow people to subscribe to an activitypub feed of your private blog similar to RSS, it's been a while since I dived into the world of activitypub community projects and tools but I am certain I saw something like that somewhere.
> there are tools that allow people to subscribe to an activitypub feed of your private blog
Those aren't relevant here. You're saying, essentially, "static sites/blogs, squeezed through a Mastodon-/ActivityPub-shaped hole". I'm saying, "Mastodon profiles, squeezed through the static site/blog hole (in a typical staticgen pipeline)". They have some words in common, but the resemblance ends there, at the superficial level; they are otherwise completely opposite ideas.
> I am certain I saw something like that
Assuming that "that" means the thing that I'm describing: you wouldn't have seen that, because the relevant Mastodon-interoperable parts of ActivityPub as they currently exist are fundamentally at odds with the ability to do this, for reasons mentioned in part by Gargron upthread.
The WebFinger thing is a big part of it. Mastodon's not alone here; there are other WebFinger-dependent protocols (like remoteStorage) that also suffer. This is covered in <https://github.com/konklone/jekyll-webfinger/tree/9bcb46bbab...>. (Mastodon has taken off in a way that we could probably say it has reached critical mass, even if it's still not as mainstream as Twitter, but remoteStorage not so much.) This is a design flaw at the protocol level, and my contention is that it impacts further adoption more than people realize. There's no good reason, for example, why when I encounter a remoteStorage-compatible app where I only ever intend to grant it read-only access, I shouldn't be able to give it the URL for a dataset hosted on a static site. Presently, however, you cannot—unless the application author deliberately implements some workaround. But they shouldn't need to.
