Bluesky is not just a shadow, it's on a pretty steady decline. Their DAU numbers are dropping every month. Which probably tells you something about the unspoken reason for this change.
Ah, I didn't realize the link I shared was Jaz's (it was shared in another comment), but they look similarly sideways over the past 6 months, with a noticeable bump in Dec / Jan.
Without researching actual numbers, it feels like that whole category of social media is pretty much uninteresting at this point. Not sure what really replaces it given that Facebook seems increasingly infested with AI slop and sponsored posts.