Leveling up Archetypes increases your max stats too

If the strategic possibilities of Archetype experimentation wasn’t enough for you, Metaphor literally rewards you with a permanent stat increase whenever a character maxes out the level of any Archetype. These increases might not individually make a huge impact on your team’s performance, but they do add up as you continue to max out each Archetype.
If you continue to use an Archetype even after hitting its respective level cap, you’ll instead earn items that boost the EXP of other Archetypes. This is a great mechanic, since you won’t be “punished” for continuing to use your favorite Archetypes. At the same time, the game couldn’t be nudging you any harder to start building different Archetypes once you get to this point. You’re literally wasting those items if you don’t!