It is massively frustrating that even though #Bluesky and the #Fediverse could be bridged, they leave tons of people in the dark on both sides. Yes, I am aware of the different protocols. But isn't it being decentralised what both networks are aiming and expected to be?
It's not simply that the protocols are technically different. They two projects work in fundamentally different ways with #BlueSky being more decentralized to its core than #ActivityPub.
ActivityPub is really centralized around instances. It's a system of instances trading content.
BlueSky is a decentralized down to users.
The BlueSky people were, reasonably, dissatisfied with the instance focus of ActivityPub. They wanted to put users at the center of the system, to respond to concerns about how administration of existing social media platforms caused problems.
There are technical concerns too, but the point is, they're not merely incompatible protocols. The platforms have fundamentally different philosophies about how to progress social media.