I'm sorry, but there's just a qualitative difference between a company setting up some API endpoints and what Bluesky PBC is doing with building atproto, releasing PDS software, encouraging self-hosters and treating them as first class, etc.
You may be interested in this thread from a core dev which examines this exact play by Reddit (and how nobody could do anything about it), how it would have been different on atproto, and how a robust ecosystem keeps incumbent players honest: https://bsky.app/profile/dholms.xyz/post/3la636r666c2p
I'll refer to Cory Doctorow's excellently-written takedown[1] of this idea. Bluesky has plans to make it technically shit-proof, but haven't executed those plans "yet". Until that's the case, they're just as susceptible as any other content platform. After all, they haven't even revealed how they will make a profit yet. And they will have to do that. Profit motive always wins, exponentially so when something is venture-backed. To quote Public Enemy: "can't truss it"
You may be interested in this thread from a core dev which examines this exact play by Reddit (and how nobody could do anything about it), how it would have been different on atproto, and how a robust ecosystem keeps incumbent players honest: https://bsky.app/profile/dholms.xyz/post/3la636r666c2p