I think what’s better is modular seats. The interior of the airplane is empty with harnesses all over the floor, and based on the passengers the seats get customized. A baby? A carrier seat is put there. Disabled? They can use their own as long as it fulfills the specs. Fat person? Combo seat. Someone wants to sleep? A bed-like is added, and so on. Plus the arrangement inside can be easily reshaped for best experience