There are protocols that make replaying the entirety of the blockchain unnecessary while still enabling confirmation of the data, gossip about gossip is one, and recently another method of hashing has arisen. By using such protocols, very low latency nodes are potential, and greatly enable scalability.
I'm not a dev, so my grasp of the cutting edge may not be relied on. I do note that technical advance eventuates, and expect it in this field as it ubiquitously impacts all. These are not the limiting factor anyway, as there's no need to scale up unless gaining users actually happens.
As long as automobiles were hand cranked failure prone devices limited to <60 mph speeds there was no need for highways. Until the social platform potentiates demand, scaling will not be demanded. Regardless of chickens and eggs, both problems require solution for Steem to survive.
I'm sure there are ideas, but it takes years to develop. Steemit Inc spent most of 2017 and 2018 focusing on scalability, which is why there were no major updates in the last 2 years. A hardfork with major protocol updates used to be every 3 months before, then it stopped while they focused on a broad range of scalability solutions - RocksDB, RC, MIRA etc. Scalability always comes before adoption, this is absolutely not a "chicken & egg" problem.
And to what end? Reddit, Twitter, Medium etc can already handle a million times greater activity. Why even bother? I wrote about this before: https://steemit.com/blockchain/@liberosist/why-blockchain-social