Phase 3 seems rather less cohesive than the earlier phases and, like everything else in the MCU, I feel that this was intentional. Part of this lack of cohesion comes in the fact that we spend very little time dealing with Infinity Stones as compared to the previous two Phases. Instead, we focus on more introductions to fill out our roster of heroes: Doctor Strange, Spider-Man, Black Panther, and others. More confusing yet, it turns out these movies are all out of order, with some even happening before the end of Phase 2's timeline.
To add a little more depth to this chaos, we get the introduction of new heroes is juxtaposed with the scattering of our established heroes, divided and broken after the events of Ultron and Civil War. This is a time of soul-searching for all involved. The theme of Phase 3 up to Infinity War (and probably beyond) would seem to be "sacrifice", as each of the characters in this lineup has to give up something, whether it be identity, home, a loved one, or their illusions.
This is a good thing, because, as I keep mentioning, Thanos is coming. And they will never make it if they aren't ready to give up everything and everyone they hold dear. As we have come along on this journey of characters, the real question will likely be: Are we, the viewers, going to be able to do the same?