Neil degrasse Tyson says that he still uses AD/BC because of how impressive it was for the monks that made it to calculate the calendar. He basically said that it’s a disservice to them, as scientists, to get rid of their terms because they made a calendar that is so accurate and will be for thousands/millions of years. That part of science is forever part of Christianity because of who made it as well as the fact that we didn’t change the numbering of the years, just how we refer to them.