Yes; and because your key is your identity, losing your key or having it stolen basically means that you have to start from scratch; there is no "I forgot my password" mechanism
Your identity, BinaryIgor only exists in ycombinator, and for as long as ycombinator allows it, and only ycombinator can allow you to change your password. I can't recall how accounts are created here, but likely it also depends on linking it to your email identity as well. If ycombinator disappears, your identity goes down with it.
In any case, AFAICT it's possible to self-host every part of the ATproto stack, and people have indeed done that. Third-party PDSes, relays, and applications/clients can talk to one another and with the ones Bluesky PBC operates. That satisfies the meaning of “decentralized” as most people use it (at least as well as other federated protocols like ActivityPub and email satisfy it).
How did you register as BinaryIgor? You and ycombinator exchanged a pubkey. ycombinator registered theirs with a DNS register, while you threw yours away.
ycombinator has 100% ownership over your identity. There is no way to prove to me you are you without ycombinator.
Having ycombinator be your naming service is useful, and so any distributed system would be wise to re-implement an analog.
But what a supernet signing scheme offers is in addition to "forgot my password" it also has a "ycombinator disappeared / betrayed our trust" feature where your ID and messages exists outside ycombinator - as long as you remember your password.
What we're currently doing: throwing away our keys and let ycombinator resign our messages with theirs; is bad for the power balance between user and the admin.