They don't do anything all that much better so never get a decent network effect. Afaik the only meaningful difference between HN and lobsters is that lobsters is invite only.

SN will attempt to overcome this by being significantly better.

1. we pay users - karma is not just an entry in a silo'd db, it's money on a global ledger ... and we have immediate plans to do a lot more wrt this
2. web of trust ranking will allow users to personalize the content they see - hybrid commons/private property vs strictly a commons
3. novel post types (e.g. jobs, eventually product hunt like posts, podcasts, bounties, classifieds, etc)
4. economic ranking algos where it makes sense - compete and pay more to get your content seen
5. marketplaces ... we have tools for sending the best money on earth around and people are here - it's natural that they'd sell stuff to each other
6. sybil resistance where it makes sense - e.g. want to send saylor a message, stake 25k sats
7. decentralizition ... unstoppable p2p social networks haven't yet existed because they don't have the means to incentivize their existence. I firmly believe Bitcoin fixes this - Bitcoin's existence is proof that such a system can exist and we'll use Bitcoin to incentivize a decentralized SN

Those are my current thoughts anyway.