Why is it that you think that content reports like this is a centralized approach? Is it perhaps because you've chosen an app which centralizes things that it feels centralized to you? This is a design decision from Amethyst that shows you all reports as posts and replies to your feed. You're choosing to pull this in. Nobody's pushing these notes to a big public relay, or in to your client. There are many bots out there, you're choosing to care about them. No other apps on Nostr show random people's reports. 

What about a bot which looks at content it finds in it's part of the nostr network and makes notes when it finds offensive language with content warnings is centralized? What about it is censorship? Do i need to send you a dictionary?