Perhaps it's the app you're using? I would say most people (at least on Lemmy, where I'm viewing this from) don't tag the OP unless there's something specific they want to draw their attention to or if they're calling them out specifically in a reply. They get notifications of all your comments so no real need to tag them. It's a lot like reddit in that respect (again, I'm on Lemmy, using the Voyager app. Another app might be different).

Edit: apparently that's a mastadon thing. Proceed.