You people are using this to always misinform Christians and spark ignorant outrage
Islamic tradition dictates that two distinct religions should not coexist within the sacred Arabian Peninsula, which contains Islam's two holiest cities, Mecca and Medina.
The entire country is treated as a unified sanctuary for Islam.
Same way you don't have a Mosque in the Vatican City.
Not having a church in Saudi Arabia does not stop Christians from practicing their Faith in Saudi Arabia. You can hold services and do your regular Christian rites privately.
Its the religious holiest state of Muslims,
they own the rights to have it abide by their religious law.
Also there are deep Christian countries like Slovakia that's banned the building of Mosques and that I have no problem with because if the population is 99.99% Christian, they can decide to officially make it a Christian state