The entire design of the architecture is for it to be driven primarily by the third party developers and the community. Bluesky the company does the bare minimum for legal compliance and every time there's an issue with legal compliance/moderation, the "first party" developers make threads to teach people how to use third party apps, etc to bypass the systems they are forced to implement.
The goal is that third party apps take over as the majority share of clients over time and the main impl should be seen as a "reference implementation".
And that of course ignores all the other non-bluesky projects currently incubating on atproto.
No matter how many times this pedantry gets repeated in this thread, this is literally not opt-in.
A light switch that is glued in place so you cannot turn it off is not opt-in.
Sure, some people with the know-how can get a pair of dikes and cut it out of the wall, the light will turn off and they will say "see, I opted out!"
But most people won't do this. At best it is misleading to say so.