Smart platform-provided algorithmic feeds like those from X, TikTok or Instagram will NEVER work on Nostr.
Anything that requires filtering from a "global feed" of all notes and delivering that to specific users will never work on Nostr because there isn't and there cannot ever be a global feed on Nostr.
If that is what you think Nostr needs to be good and popular then you'll first have to destroy Nostr by turning it into something else, and then you can implement it.
The alternative is to create something new, a new way of doing discovery, something that actually works nicely within the Nostr constraints, something that actually only works on Nostr because only Nostr has these distributed independent servers with specific owners, specific rules, different users, personalities and preferences.
It supports all sorts of RSS feed discovery from HTTP URLs and renders them beautifully in a simple straightforward interface, you can also paste nostr:... URIs, including nip05, npub and nprofile codes (they should also work without the nostr: prefix).
Even if we ignore the bad psychological and societal effects of such practices and assume they are good, and even if we assume that Nostr is all running in a single server that has all the events (a Bluesky-like unavoidable requirement for such universal consistency) these people are still completely oblivious to the fact that anyone can create a bazillion keypairs and spam like counts.
So when they ask for a "universal consistent like count" what these people are really asking for is for a centralized KYC barrier at the doors of Nostr that ensures only a single keypair can be created by each human.
Outbox model is not being challenged, I still think outbox model should be the de facto standard, but it can be complemented. I don't think anyone should implement a thing that just does the inbox model, that would be very limiting -- i.e. you would never be able to follow anyone who doesn't do the publish-to-inbox flow on their side.
But I guess you could have a third-party service automatically forwarding stuff from outboxes to inboxes. Is there a risk to doing this?
They must still have an outbox relay unless they really want to not get their message out in the world for all to see -- which is the default behavior for people who use Twitter and so on.
I heard that there is an ongoing movement now for people that truly care about decentralization and censorship-resistance to only publish to small relays.
I didn't mean to downplay the challenges, and I don't even think outbox/gossip model is the only solution or the best (although I can't think of anything better at this point). All I did was to complain about the current state of things and wish they were better.