The change is very marked in both the North and the South.
While names tended to have a theological basis even 50-75 yrs ago, they are now getting more secular by the day.
The names that abound today are these -
Amit, Neha, Ajay, Vijay, Vikas, Ankush, Ankit, Adarsh, Anshu, Anshul, Viraat, Nikhil, Neeraj, Priya, Preeti, Pankaj...
Sure, these are all Sanskritic Tatsama words. But they are not theological as they once used to be.
They have turned passe in barely a couple of generations
Prakrit names are increasingly passe in Northern India. At least in Urban areas.
Maybe the names are still used in smaller towns and villages. But in the large towns, it is safe to say they are extinct.
Also like the North, sanskritization of names has happened apace.
Names like Magizhmaran, Umberkoman, AravAmudhan - prevalent among Sri-Vaishnava brahmins some 100 yrs ago. Very rare today.
Both in the North and the South
Why do we not dig into scriptures any more for names? To my mind this cannot be delinked from the larger process of secularization in society and the reduced role of religion in our lives.
It is not necessarily something I embrace, as it smacks of pretence. The rootedness that emanated from a name like aravAmudhan or Kanhaiyalal is missing in chic Tatsama names like Ankush or Vikalp
The first names remain v much Christian with a strong theological basis, with the odd Greco Roman exception (like say Horace, or Alexander)
John (Adams), Alexander (Hamilton), George (Washington), Benjamin (Franklin), Thomas (Jefferson).
All these first names remain EXTREMELY common to this day
Worth pondering over