The idea of a global firehose feed is impossible. Nostr is barely used and already its impossible to find any note worth reading if you look at the global firehose feed. Every relay that doesn't make use of some form of heuristic based automatic filter will get DDOSed at some point by petabytes of spam. WOT is just one tactic to sort it. The prevailing alternative will probably be paid relays, but even the tiniest payment is a hard sell when people are used to the internet being free. So much of the internet is just a massive struggle against the inevitable end where everything is monetized. Lightning micropayments make this possible.

Think about the lack of advertising on nostr. Like if nostr was Facebook or Twitter right now, a pretty portion of those users would seriously be willing to pay a micro transaction to remove all the advertisements. People don't realise how good nostr is without ads because it never had them. The people who would pay to remove ads from other social media, those people should all be willing to contribute to relays for an improved experience. But they probably wouldn't see the point because nostr already does not have ads. I think the real issue is user friendliness. I barely understand how to configure the relays, actually I don't even barely understand, I haven't bothered to learn yet. The easier it gets for the common non tech users the easier it'll get for everyone else I think.

Sorry if I am mistaken, but if your relay is private (you run your own) then DDS attacks are not possible as only activities of my nsec get saved there. Or am I missing something?

this is why wot relays are dumb. wot should be done on the client