Threads is the one plummeting in "extremely rapid fashion", losing 81% of their DAUs. [1] That doesn't mean that it is dead, it just means that not only the media desperately projected these hype stories for their Threads clickbait but as many incorrectly predicted, it ultimately failed to overtake Twitter / X. Even more statistics here [2] and [3] show that Threads was hardly the "Twitter / X killer" as predicted. Both will co-exist but it seems all those predictions were erroneous.
For Threads to have around 8 million daily active users means it is still easily eclipses the entire daily and monthly active usage of Fediverse according to the stats here under "Average All Active Users by Month". [4]
[0] https://news.ycombinator.com/item?id=36580669
[1] https://www.businessinsider.com/threads-meta-app-decrease-da...
[2] https://www.businessofapps.com/data/threads-statistics/
[3] https://www.similarweb.com/blog/insights/social-media-news/t...
Elon keeps Eloning, so inevitably there will be more controversies that make users look for something else, and Threads will be there for them.