Bluesky is not the protocol bluesky runs on. Pretty convinced by now that there are like 6 people on nostr that have seriously looked into how farcaster, atproto, holepunch/keet, or any of the others in the vein actually work.
Discussion
I do not get your point. When the Plattform Bluesky locks down its content and you say it is not the protocol, how is someone supposted to create an API then?
Pull directly from the PDSs, or from the other relays that have nothing to do with Bluesky's own infra, and use that as the foundation for your API. It's been done and is being done.
Ok. So then your point is, that PDSs have still access and they offer APIs?
Any relay can establish a websocket connection to any PDS's xrpc (firehose) endpoint. But such relays already exist and are not run by bluesky, so you can go through one of those, or make your own, limit the backfill to run on a cheap VM if you want.
You might want to read up on the protocol architecture over there first. Once you've got the basics then happy to debate about it.