Late 20ties is miles different than early 20ties, especially for those who went to college. Very very different. Anything over 22 does not count as "barely into adulthood". 23 years old are adults in all meanings of the word.
26 year old dudes are adults, full stop. And in my experience, they don't think nor act like teenagers whether they settled down or not, whether they married or not, whether they kept old hobbies or not.