Generally I agree on the loss of momentum. I’m in there and have said the same there.
That being said, comparing it to mastodon in terms of size at the moment doesn’t make sense. The current metric indicate the BlueSky user base is likely bigger than mastodon’s. Not by much and certainly, just like mastodon, no where close to competing with Twitter and threads (if that’s the goal).
But it seems to have a user base roughly on the same scale as the fediverse. Which is something given how slow and behind they are.
Big question is how viable a small user base is for their company behind it and whether the structure of their system is something a community organisation could keep afloat.