The problem is partially that bluesky isn't really the Fediverse. It doesn't use the standard, and isn't truly interoperable. Accounts can be bridged, but that's a hacky workaround, not actual intercompatibility.

And threads is run by a company whose human rights violations would take a week just to read out loud.

The idea that the specific platform doesn't matter isn't a blanket statement, it's a description of being interoperable, nothing more. Bluesky isn't truly interoperable, and threads is run by Meta who facilitated ethnic cleansing, mass rape, and the burning of whole villages in Myanmar despite countless explicit warnings that these things would happen if they didn't take safety measures (not to mention all the other garbage Meta has done or enabled)