I'm a lot more optimistic (aka naive) than most it seems.
I'm really new to all this fediverse stuff, but I believe we can't lose what we already have, people that are here before Threads, will probably be here after Threads, since we already made that decision to leave reddit or twitter, to leave all that behind is a big social sacrifice.
My red line for Threads will be if they start to mess with the standards and the ActivityPub protocol, acting in bad faith.