You're right in some particulars, both gambling and insurance let customers enter transactions with an uncertain payoff that favors the house, and both are relatively aggressive legally when customers try to get an edge.

But the purpose of healthy gambling is to have fun, and the purpose of insurance is to pay a small amount in most future states of the world to avoid very bad outcomes in some future states of the world. These are both reasonable things to spend money on, but they're very different objectives.