so naturally, and not being on top of the technicals, I'm asking myself why it couldn't be done if we have Block already. We have Unfollow on other apps, Strava for example.
technical: blocking creates a app.bsky.graph.block in your own repository, which makes any authenticated attempt by the subject to interact with your repo impossible through the AppView.
Unfollowing would require the app to remove a app.bsky.graph.follow from someone else's repo—which is inpossible