After the Islamic countries in Saudi Arabia agreed to unify the beginning and end of Ramadan, why was that not done? And what is the religious ruling for Muslims in countries that violated this consensus?

Islamic countries have not agreed on a single sighting for the month of Ramadan due to the difference in moonrise locations, which is supported by the hadith of Kuraib, the freed slave of Ibn Abbas, where Ibn Abbas did not rely on the sighting of the moon by the people of Shaam. This indicates that the difference in moonrise locations is considered in Sharia. As for the Day of Arafah, a unified sighting is necessary because the pilgrims are in one place.