You can care because trust and authenticity are different things. A bridge account is a proxy, not the person. If the goal is just content consumption, sure, it works fine. But if the goal is proof of authorship, cryptographic identity, or building a verifiable reputation that follows you across apps, a bridge breaks all of that. You get the posts but lose what makes Nostr useful in the first place, no middleman, no one who can impersonate or censor you, no server that decides what you see. Plenty of people do care about that difference. That's why they're here.

The proof of authorship is irrelevant since Twitter is a trusted platform. There is no way to prove anything. You have to trust the company is not fucking around with people's posts.