1. Religious neutrality. The terms BC and AD are derived from the Latin phrases "ante Christum" (before Christ) and "anno Domini" (in the year of the Lord), which refer to the birth of Jesus Christ. For people who do not follow Christianity, these terms can be seen as offensive or exclusionary. BCE and CE are more neutral terms that do not reference any particular religion.
2. Historical accuracy. The year 1 AD is traditionally believed to be the year of Jesus' birth, but this date is actually uncertain. Some historians believe that Jesus was actually born a few years earlier or later. BCE and CE allow for this uncertainty by not specifying a specific year for the start of the common era.
3. International standardization. BCE and CE are used in most countries around the world, except for the United States and a few other countries. This can be confusing for people who are trying to communicate with people from different countries. Using BCE and CE helps to avoid confusion and promote international standardization.
The movement to use BCE and CE is still ongoing, and there is no consensus on whether these terms should completely replace BC and AD. However, the arguments for using BCE and CE are strong, and it is likely that these terms will become more common in the future.