First I reject your ridiculous question as answering it directly implies I agree with you that Nostr’s utility is minimized which just isn’t true. I’ll instead educate you on how Nostr works.
Nostr is not a social network but a protocol on top of which social networks (domains/spaces where speech can take place) can be built. The implication of this is that you can indeed build your own version in which you can restrict other people’s speech if you wish.
NIP-72 allows for Moderated Communities to be built on top of Nostr, in which spaces can be created and restricted to a moderators content. The moderator you are subject to approves every post you make to that community. This is great for Reddit like communities that focus on a specific topic and have rules on the content that can be shared. Assuming your posts are rejected (or you get outright banned) from a community, that ban does not extend automatically to other communities unless all moderators agree on silencing you.
The identity function of Nostr makes it so that you can reuse the same identity across all of you wish (but you don’t have to) but you don’t have to.
But you can’t ban an identity from the entirety of Nostr, it’s not technically feasible. The identity layer of Nostr is completely decentralized and there’s no authority granting access (or denying it). If you run a relay you can indeed control the pubkeys that can post to your own relay (after all it’s yours) but you can’t demand others to do the same.
This is unlike the original NIP-01 which introduces event kind 1, allowing for a Twitter-like social network or public forum to be built on top of Nostr. Kind 1 posts are 100% public and as long as they adhere to the schema specified in the protocol they will be accepted and relayed regardless of their content. This public forum might be too much for some or at times and that is understandable so there are tools like muting someone from your view… but being here is a choice and nobody is forced to use this. What NIP-01 does not give anyone is absolute power to silence the speech of others: everyone is treated equally.
That’s the best freedom anyone can hope for.
Hope that helps.