What Digimon is supposedly about:
A bunch of kids are tasked with saving two parallel worlds from the forces of evil. Fighting monsters are involved.
What Digimon is actually about:
A bunch of kids are forced to face all of their personal insecurities and familial problems, compiled with one or two painful backstories, along the way bonding with creatures who probably understand them better than they understand themselves and encountering a number of traumatic experiences. Large amounts of character development are involved.