I think there are aspects hard to convey in trailers such as atmosphere and sound design. It's more about planting ideas and making you think and discuss afterward, it isn't entertaining in the traditional sense. Some people I know that saw it stated they didn't get the big deal while watching, but it stuck with them and found themselves wanting to talk about it and even see it a second time.
I’m usually not big on sci if movies but I really enjoyed ‘Arrival’ and ‘Moon’is one of my favourite movies ever. So I guess I’ll check it out this week before it’s out of theatres.