A surprising found by Rene Pickhardt is that over time the Lightning network fees rise and the reliability drops. He did propose some solutions in this talk.
#Lightning
Discussion
Multi-party channels is the main proposal he thinks we should pursue.
Seems like IP routing has the same or similar issue that LN has. While it doesnt have "fees", you can kind of think of ping time as a fee. The bigger the graph gets, the more hops you have to take, and the longer the request takes. This drives networking toward many nodes connecting to central router for efficiency. I expect LN to solve this issue in a similar manner.
Interesting. Sort of like a self-organizing into a hub and spoke system.