Judge me if you want, but I created a Threads account - mostly to prevent impersonation, but also a bit out of curiosity.
Millions of users or not, it is at least at the moment a pretty lousy alternative to the Fediverse. Aside from my hatred of Meta, the feed is utter trash with no way to manage it, I can't even set a profile photo, and replies inexplicably don't show up. These are really basic design and usability issues that, if not addressed, will tank longer term user numbers