Isn’t this typically explained via marginal utility, not just utility? You can’t really compare the utility of the same amount of money in the hands of differen

Isn’t this typically explained via marginal utility, not just utility? You can’t really compare the utility of the same amount of money in the hands of different people, but for a single person each additional unit of money is worth less than the last along some non-linear curve. The $1k you spend on insurance is further along this curve than the first $1k of the insured loss (and the second, and the third, etc) and if you do the naive expected value calculation it ignores this curve.