Iirc Apple and some other companies threw a bunch of money at LG so they can get in the game as well, which will be nice in the future but atm obviously screen quality is worse and costs are higher due to R&D cost.
PPI is not a fixed number determined by generation and isn’t relevant. Brightness is an interesting point but my Nexus 6 was AMOLED (oh my) and <400 nits so significantly dimmer than the iPhone X.
It’s very possible, even likely, that Samsung’s latest flagship phones use newer display tech than the iPhone X. It is exceedingly unlikely that the iPhone X is using first generation tech.
In the tests I've seen the iPhone comes out on top in almost all situations vs. the Pixel, as a representative example here of a very good Android camera, with the notable exception of extreme low light conditions.
If they complete the whole package and make it all work great, then like the iPod, it doesn't need to be first to market to be revolutionary. Just be better than all the other implementations and UX thus far. Though iOS 11 doesn't seem like that's all coming together super great but their pros still seem to outweigh all their competitors cons for what I want from a device. And of course, marketing is marketing.