One of my favorite things about Xenoblade X was how the vast majority of the cast were adults and how the topics of conversation fit that higher average age range.
For the core cast, you have:
Elma 29
Lao 31
Doug 30
Irina 27
Gwin 24
And of the recruitable characters you have:
Alexa 21
Boze 54
Frye 30
Phog 24
Hope 24
HB 28
Murderess 26
Nagi 57
Yelv 22
The only characters younger than 20 are:
Mia 19
Celica 18
Lin 13
Was kind of refreshing seeing JRPG characters chat about basic co-worker small talk topics like kids, alcohol, cars, sports, etc. I don't know about well-functioning since there's a lot of alcoholism and depression going on in there but uh... Those are pretty adult problems to have at least?
Also the world just ended. Billions of people died and these guys have been fighting a war against a hostile alien force for years