The catch is that the whole system is effectively centralised on BlueSky backend services (basically the relay). So while the protocol may be standardised and open, and interpreted with decentralised components, they’ll control the core service. Which means they can unilaterally decide to introduce profitable things like ads and charging for features.
The promise of the system though is that it provides for various levels of independence that can all connect to each other, so people with different needs and capabilities can all find their spot in the ecosystem. Whether that happens is a big question. Generally I’d say I’m optimistic about the ideas and architecture, but unsure about whether the community around it will get it to what I think it should be.