You will also see “BCE” and it means Before Common Era, which replaces BC, which means “Before Christ”.
The newer terms are more inclusive.
The Georgian calendar (at least in the numbering of years) is a Christian construct, and it therefore makes sense to name year 0 after the year of Christ's birth. Whether or not one acknowledges his lordship or whatever, you are still operating in the Western tradition which is impossible to understand without Christianity.
It's just petty power tripping. Some people have that need to feel superior by swapping the dating system to something meaningless and arbitrary. What makes this era "Common"? Presumably the birth of Christ, since that's still when you are setting the origin of years. So the rename is utterly pointless. It's still A.D and should be referred to as such.
I'd have more respect if these revisionists went full Jacobin and plonked Year 1 down as some new date, and named the calendar after something new.
To me it seems to exclude the only person referenced in the original form.
On the other hand I’m glad we’ve all converted on one common reference for dates and don’t have one for each sphere of influence, cuz then something published in China vs Japan vs Taiwan vs Europe and the Americas vs Egypt vs… who knows what would be messy.
At least most places that use other calendars also keep track of the Western year in parallel.
My Thai wife was born 543 years after me, even though we were born in the same year. ("Hi, this is my wife, from the future!") Our wedding certificate contains only the Thai year. As I remember, for official purposes, Japan counts years of the current emperor's reign, along with an official name for each reign.