Two things..
The Abrahamic God is a non-physical entity that is responsible for creating and maintaining the universe.
As are the gods of other religions. No religion I am familiar with believes its gods are physical beings. They may manifest but they are spirit not physical.
..so "other gods" might be true, or might be false.
It all depends .. it is hard to believe that a statue could be God, for example, because a statue cannot create a universe.
The error in that thinking is that worshipers believe the statue or idol is God. No one of any Pagan religion believes an inanimate object is God. The "idol" is a conduit to God. You don't talk to the telephone, you talk through the telephone to the person on the other end. The telephone carries energy, the idol carries energy.