As I said, they're not flawless, but they can definitely help. Coming up with an example in which they break doesn't imply they're horrible and should not be used.

You have just cited a wrong claim from the hodlbod without addressing any of my points. In case you want to do that, here are some more points for you to address:

quoting naddr1qq…x8e4

Why relay hints are important

Recently Coracle has removed support for following relay hints in Nostr event references.

Supposedly Coracle is now relying only on public key hints and kind:10002 events to determine where to fetch events from a user. That is a catastrophic idea that destroys much of Nostr’s flexibility for no gain at all.

• Someone makes a post inside a community (either a NIP-29 community or a NIP-87 community) and others want to refer to that post in discussions in the external Nostr world of kind:1s – now that cannot work because the person who created the post doesn’t have the relays specific to those communities in their outbox list;
• There is a discussion happening in a niche relay, for example, a relay that can only be accessed by the participants of a conference for the duration of that conference – since that relay is not in anyone’s public outbox list, it’s impossible for anyone outside of the conference to ever refer to these events;
• Some big public relays, say, relay.damus.io, decide to nuke their databases or periodically delete old events, a user keeps using that big relay as their outbox because it is fast and reliable, but chooses to archive their old events in a dedicated archival relay, say, cellar.nostr.wine, while prudently not including that in their outbox list because that would make no sense – now it is impossible for anyone to refer to old notes from this user even though they are publicly accessible in cellar.nostr.wine;
• There are topical relays that curate content relating to niche (non-microblogging) topics, say, cooking recipes, and users choose to publish their recipes to these relays only – but now they can’t refer to these relays in the external Nostr world of kind:1s because these topical relays are not in their outbox lists.
• Suppose a user wants to maintain two different identities under the same keypair, say, one identity only talks about soccer in English, while the other only talks about art history in French, and the user very prudently keeps two different kind:10002 events in two different sets of “indexer” relays (or does it in some better way of announcing different relay sets) – now one of this user’s audiences cannot ever see notes created by him with their other persona, one half of the content of this user will be inacessible to the other half and vice-versa.
• If for any reason a relay does not want to accept events of a certain kind a user may publish to other relays, and it would all work fine if the user referenced that externally-published event from a normal event, but now that externally-published event is not reachable because the external relay is not in the user’s outbox list.
• If someone, say, Alex Jones, is hard-banned everywhere and cannot event broadcast kind:10002 events to any of the commonly used index relays, that person will now appear as banned in most clients: in an ideal world in which clients followed nprofile and other relay hints Alex Jones could still live a normal Nostr life: he would print business cards with his nprofile instead of an npub and clients would immediately know from what relay to fetch his posts. When other users shared his posts or replied to it, they would include a relay hint to his personal relay and others would be able to see and then start following him on that relay directly – now Alex Jones’s events cannot be read by anyone that doesn’t already know his relay.