Yes, probably you could say that eventually lightning could replace everything, but make more focused:
-
torrent sites: easily the best use case, instead of getting through dozen of ads to get the damn file, your paid a small amount and ready.
-
Netflix alternatives: getting every service to watch a show isn't worth it. Why not a alternative service that concentrate all those shows and movies?, Paid monthly membership and voila.
-
Roms sites: just like above, pay and get the file, no ad, not waiting times.
-
deep learning services: old photos restoration, chatbots, colorization, etc.
That come to my mind as user case that could be really useful. Also your could add Uber alternatives. Went do it think?, What would you add to the list? .