How is it mean to say that nostr:npub1getal6ykt05fsz5nqu4uld09nfj3y3qxmv8crys4aeut53unfvlqr80nfm is a centralized service?

Where does the nostr:npub1getal6ykt05fsz5nqu4uld09nfj3y3qxmv8crys4aeut53unfvlqr80nfm software run from? A centralized server

Also, how is nostr:npub1getal6ykt05fsz5nqu4uld09nfj3y3qxmv8crys4aeut53unfvlqr80nfm existing, more important than educating people to stay away from centralized data honey pots like nostr:npub1getal6ykt05fsz5nqu4uld09nfj3y3qxmv8crys4aeut53unfvlqr80nfm ?

Anything centralized and having controlled access (invite links, email capture etc) is against the principle of #bitcoin being open to anyone, anywhere, anytime, with no questions asked