1. Preserve the shape of the food being cooked. The older non-electric cooker would mush all the garbanzo beans or vegetables into a mash. When I cooked with the instant pot for the first time, I thought nothing was cooked fully because every vegetable and bean still were mostly in its original shape.
2. No noise. Non-electric cookers have the steam whistle to vent out excess steam which is noisy and annoying. Instant pot does not have that.
3. It has two pressure settings - lo and high pressure. When I bought it, very few of them offered this option.
Most electric pressure cookers come with a coated aluminum pot. Instant Pot was one of the first ones to offer a stainless steel container. This was the original reason I bought an Instant Pot.