What is the ruling on one who did not pray until the age of 16—will their prayers be accepted?

Whoever abandons prayer until they reach the age of sixteen must perform sincere repentance and make up for all the prayers they missed since puberty. Their prayers, God willing, are accepted, based on the Almighty's saying: (And whatever good they do, they will not be denied for it; and Allah is Knowing of those who fear Him).