Who in Mexico decided to celebrate the day of dead?

The celebration of the Day of the Dead (Día de Muertos) in Mexico originated from ancient Mesoamerican indigenous cultures, such as the Aztecs and Maya, and was further influenced by Spanish religious traditions during the colonial period.

It was the indigenous people who established and practiced the rituals and ceremonies to honor and remember their deceased loved ones, which later merged with the Catholic commemoration of All Souls' Day and All Saints' Day.