Hashtags do not replace groups.
No one moderates them. They’re easy to hijack and spam. And there’s simply no permanence to them.
Which is why, if you actually want to discuss something, it’s better to tag a group. For example, if you want to be part of an actual PC gaming community on the Fediverse, it’s better to tag @pcgaming@lemmy.ca than #pcgaming.
This needs to be common knowledge because people new to the Fediverse do not know about groups. Hell, I’d say people who have had Mastodon accounts for years still don’t know. And that’s a shame.
@fediverse@lemmy.world
That’s entirely dependent on the interface switching, or some kind of universal interface. That’s the part I have serous doubts about. Keep in mind you have to make a single interface that work better than all the others on their respective native systems. I’m not sure that’s possible.
You don’t need to make a single interface, just a “meta-interface” that allows you to switch UIs on the fly.
That’s entirely doable within a client.