Bitcoin is very hard to use by most people. People aggressively argue with me about this, but try sending someone new 1 sat to demonstrate the technology? No you can't. (I've literally been accused of "missing the plot" (what plot, bro?) by pointing out that very small transactions on lightning may be extremely uneconomical due to base fees on routing nodes). The whole lightning "you need money to receive money, but don't worry, it's only at the start" betrays the great ignorance on the bitcoiners part.

Also people like DarthCoin love to insult people for being stupid and that he doesn't need them, but if you want widely accepted money you will need not only people you think are stupid, but actually stupid people to use it. Furthermore you need to accept that your actual enemies and people who you hate or they hate you should also be able to use it.

On the technical side I don't see a scalable solution that will scale for all the people on earth. But for this part I am hopeful that it is solved (once upon a time I didn't expect something like lightning either).