One of the few seasons that clearly dealt with friendships and relationships, and the only one that dealt with the psychology of the characters much deeper.1.Mallow lost her mother at a young age, worked herself at a young age helping her father, then had a goal to cook well. Maybe this goal is mundane but everyone has some goals besides cooking is not bad, there are many anime about cooking that conquer almost every pokemon character
2. Lana is closed in herself, only later she opens up to people more, her father is almost not at home, her mother brings up two children.
3. Lillie's childhood trauma and then gradually overcoming it
Just because each of these characters isn't aiming to become Miss Pokemon or Pokemon Master doesn't mean they're bottomless or weak.