So, in conclusion and IMHO, BlueSky is a successful Twitter alternative.
The Fediverse including Mastodon is not. The fediverse is a fundamentally different and bigger thing due to its truly federated nature.
And both can have their place in the market of attention.
One ultimately is a commercial endeavour while the other is not. But for the general audience that simply is not the decisive factor. One can find that A Bad Thing, or one can shrug and move on in ones preferred direction :)