Commodities are goods whose properties are standardized and, frequently, graded by an authority. As you give examples of yourself, the real test is what happens long after the initial purchase. Figuring out that side of the bargain takes more than a few minutes getting a price quote.

Car insurance is definitely not like a given electronic item, which is made to the same standards by a single manufacturer. It it's like some nerd purchase, it's more like flash drives. In theory commodities, manufacturers have a complicated set of incentives and the actual quality of the product may be hard to determine without extensive use.

I'm not against people shopping around. If people want to invest the time, by all means do it. But I object to the notion it's as simple as getting a quote. Getting more options can in fact sometimes mean a bad thing if you switch from a proven-reliable product to something that is cheaper up front but worse later.