Your report should inform your web of trust of an issue. It should go to your relays, and your followers can decide what to do with it. Trust it and block the reportee or disregard it.
Discussion
I agree that web of trust needs to be involved.
But:
1) you shouldn't have one web of trust, you should have many. In particular, you should have one web of trust for each type of content that annoys you. You should have a web of trust to filter shitcoin content, another web of trust to filter unwanted sexual attention, etc.
2) manually blocking reported npubs shouldn't be the only option - not scalable. You should be able to subscribe to a content-specific group, to which you delegate the ability to block offending npubs for you.