yes, bsky is Literally Twitter. that is, in fact, the point. it's scalable (as scalable as a service like that can be) but if needs be parts of it can be hosted by somebody else without much friction
this is literally why atproto is interesting. this network just would not be able to survive some few dozen million flooding it. it also has trouble with stuff like propagating counters since it would put unnecessary load on servers, while in atproto that's handled by people/orgs that have more computing power than a 4gb model of rpi 4b
