Really? I have lived in Iran and the Kingdom. They are not competitors.
“They are not competitors.”
Shows what you know about Islam.
Yes, they are competitors.
Iran has the “holy city of Qom”, their Shiite shrine where the Twelvers hope the Muslim messiah, the Mahdi, will appear to spread blood and destruction to the infidel.
Saudi Arabia has Mecca, where supposedly Mohammed was handed a moonrock by Allah.
[Allah being a pre-Islamic pagan moon deity..]
So you have the Shias in competition with the Sunnis, Sufi, Wahhabi, etc..