Religion is founded on belief, and belief allows people to feel certainty about things they're ultimately uncertain about. As long is there is something that someone doesn't fully understand, religion and god are a solution to bridge the gap.

When you are that person, the leap to a god is fairly logical and easy to them, since at a base level, it's born out of a desire for someone to be in charge and in control. You understand some of the world around you. To understand it more fully, you just need a bigger, stronger, smarter version of yourself. That's why in most religions, a god is not some transcendent, immortal, eternal, all powerful being. They're just essentially Human+. There are way more religions with gods like Zeus than Allah. Saying that nobody is in charge, and nobody fully understands anything, and that's all OK makes billions of people uncomfortable. And, screaming at them that they're wrong and need to be more OK with some existential dread usually just serves to make them more uncomfortable.