In the next 20-25 years what will the age of adulthood probably be raised too?

The age of majority is 18 in most states except Alabama 19,Nebraska 19, and Mississppi 21 and I think it should be 21 in every state I used to think.I think that the age of adulthoo should be 30 worldwide cause 18-29 is "Emerging Adulthood" where you are no longer an adolescent but not yet grown and at 30 you become a young adult.The life expectancy is increasing and people are living longer can have babies at a longer age so I think that the age of adulthood should be raised.The brain is developing into the 20's also.