my prediction on this is that stuff like NWC in nostr, combined with a replication consensus protocol for things like a name service protocol (i'm making one called Free Internet Daemon), will be where the legitimate progress with lightning happens.
lightning has no consensus, so individuals are the atom of the security. with a consensus system, where multiple parties can decentralize a coordination system, according to an appropriate set of rules for the process, things that we see currently centralized in for example the alby hub isolated wallets, can become a protocol.
once you get to the point where you can trustlessly coordinate such a group wallet, and the consensus has full 50% byzantine fault tolerance, like bitcoin (my design has this property, it uses web of trust attestations) then we have solved the increase users problem. increase transactions solution is a prerequisite.
anyhow. that's one of the half dozen little side things i'm doing at the moment. i probably should focus on that one more because my most favourite programming task is designing and implementing a novel consensus protocol.