The 18 quintillion planets universe has never been a compelling argument for me. It's just a reframing of the "procedurally generated level" which is something we've seen in hundreds of games already. Spelunky has, effectively, 18 quintillion levels. More than that. Endless. If you had every person on earth play Spelunky around the clock for 18 billion years they still wouldn't see every possible level. NMS has just framed this old idea in a compelling new way, but, really, it's not new.
You can get a sense of what types of things are going to appear on planets pretty quickly. My experience and the experience of my friends with the game has been pretty much the same from planet to planet with little variation.
It's a boring, boring, boring game IMO.