ELI5: What’s the point of a deductible?

I don’t understand it. I could be paying a health insurance company hundred of dollars a month and I still have to spend thousands before coverage kicks in. Why am I paying them for nothing in exchange?

I know insurance companies exist solely to make money, and constantly screw people over (sometimes to the point of people losing their lives). Is this just another thing that’s been so normalized that no one questions it? Or is there an actual reasonable explanation for it?