something my friend pointed out when i forced him to watch wicked for good:
glinda's chorus in 'for good' is talking about huge, big things, comets and boulders, whereas elphaba's talks about a seed and a ship.
glinda's reflects that elphaba is everything to glinda, she has changed her and will always be with her. but elphaba's in comparison is like "yeah you were a part of my life, but i'm moving on now, i can get over it"
personally, i choose to believe they are both incredibly down bad for each other, but this, paired with ariana grande saying in an interview (i forget which one so you'll just have to trust me) that "the way glinda loves elphaba is very different from how elphaba loves her" (as a response to why glinda can't know elphaba's still alive) really seems like it could be a case of unrequited love making the love triangle look sorta like this:
which i think is really funny (in a sad way)