I think it would be more appropriate to say it's the only film which we know has any bearing on the storyline in Avengers: Doomsday so far. (Pretty egregious then that the casting announcement has none of the 'Marvels' in it.)

Everything else seems to have only been setting up abandoned tangents.

Also agree this film is underrated and buried by culture war aggression. It's not amazing by any stretch but it's on par with the average Phase 2 film and probably the best Phase 5 film after Guardians 3.