@squirreltalk As mentioned in my post, that is the only Playbook that cannot be easily adapted for both teens and adults. And that is only because you play a time-traveled younger version of yourself. Literally any other playbook can be easily used by all ages. Even the Newborn doesn't have to be young in terms of years. Think Dr. Who for that one if you want. Or it can be young in age but not in mind (Vision ala MCU).
The Bull, the Star, the Legacy, the Outsider, the Transformed, the Doomed, the Delinquent, the Brain, the Soldier, the Janus, the Scion, the Nova, the Nomad, the Reformed... even the Protege doesn't have to be young just inexperienced. But seriously... look at any of the playbooks available and the DC/Marvel influence becomes VERY clear. Most of the characters used as influence for the playbooks were not teenagers.
You also aren't confined to a single playbook. The Hero's Moment each character strives towards doesn't necessarily require the character's story to end. It might mean you simply... change paths. There's no need to worry about xp bloat or 'dinosaur' players going all One Ring on everyone, because its less about the Moves than the Influence. And Influence changes ALL the TIME. It affects you both positively and negatively, but always with an eye to progressing your story both individually and collectively.
NGL, one of the MOST fun games I ever played with friends was a Scooby-Doo-ish version of MASKS. We all picked playbooks that mirrored our favorite SD characters, grouped up, and went out to solve mysteries! I did a campaign where we did the full on Super Teen High School setting. The Young Adult hero group out to prove themselves. That group turned into the seasoned and older group of Mentor Heroes that each took on a protege/successor/child/etc. to teach.
The possibilities are damn near endless. The system is crunchy enough to resolve conflicts but flexible enough that it will never interfere with the story. And the story is literally what you make of it. True collaborative storytelling.