The entire point of the fediverse is that there is no “we”. Or rather, you can decide which “we” you want to engage with. Look at behaw. When world started exploding with growth, the beehaw instance defederated because they wanted to preserve a smaller community.
I will never sign up for Threads or any other Meta service. However, if the fediverse allows me to interact with my friends and colleagues who have without having to give up all my data to do so, that’s a win in my book.
So feel free to go start or join an instance that defederates from Threads. Just stop expecting everyone else to do so.