Jerusalem has been a significant city of the eastern Mediterranean world for thousands of years, so multiple religions with eastern Mediterranean roots sharing significance for that city is hardly surprising.
IIRC a similar coincidence has formed in SEA where a particular mountain has gained religious significance for local Christians Muslims and Buddhists, although with much less international controversy over it.
The case of the temple mount in particular is especially weird since it’s a part of zealous Christian and Jewish prophetic narratives (despite revelations saying getting the rapture to happen by checking a list is a fool’s errand and non zionist consensus among jews agreeing that the “third temple” is the state of internationalization and diaspora which the destruction of the second temple initiated) and also being a major site of religious history to Muslims, with the site apparently being where Mohammed ascended to heaven at the end of his life.
There’s a church in Jerusalem with a ladder still left up there from the 1800s because all christian denominations that share control over the site can’t agree to remove the ladder, so you can imagine how hard the squabbling goes when not even the base religion is held in common.