All this says is that the interection with twitter is larger than it is with threads. By this logic Instagram must be dead and burried given that the last HN post from instagram.com was 37 days ago.
Threads was never as big as Twitter. They're literally days old (15 days). I'm not sure why it's expected to match or outmatch Twitter in anything currently.
Problem is it's a network effect. If you can't overcome it quickly it's basically dead. Sure people could slowly switch over, but why would they? Seems like there's no content there to switch over too. Looks just like Google +. Massive quick sign ups driven by existing platform, but no real activity.
Threads has access to 1+ billion Instagram users, so how's that for network effects? And next time Musk does something stupid, people will flood alternatives again.
This is why it was important to launch the application, even though it was clearly not complete. They just added hashtags by the way.
https://news.ycombinator.com/from?site=instagram.com