@heatherhorns_lite @chirpbirb @Gulfie because it federates over atproto instead of activitypub. And bluesky also federates over atproto.

One of the practical differences between atproto and activitypub is that with activitypub, it's possible to self-host a fedi instance on an old 3DS (figuratively speaking), while with atproto, your computing and storage capacity have to match the size of the network, and are already in the range of like six digits of $$ per month.
So in activitypub there is mastodon dot social with like 30% of fedi network there, and thousands of completely independent instances which wouldn't care if mastodon dot social would disappear one day or if it would block them.
While with atproto, not counting PDSes and other small "self-hosted" things that still depend on bluesky infra and on bluesky existing and not blocking them specifically for idk "harassing" terfs, there are basically two instances: bluesky with 99.99% of all userbase, and blacksky with 0.01% (and it took blacksky four years and tons of effort and money to break bluesky monopoly, and keeps taking tons of money just to run the thing).