There was a pretty intense astroturfing campaign on reddit for it in the run up to the last US election. I wouldn't be surprised if there were some American leftist political money there, to have a social media not controlled by Musk.

Their funding is at least $23 million, without knowing what the latest round netted them.

https://www.businessinsider.com/x-competitor-bluesky-valuation-new-funding-round-2025-1