Tbf, an instant pot can replace a slow cooker and pressure cooker, and so is less of a single use item. And the air fryer is kinda just a riff on the toaster oven, and imo, this is a good thing for the american pallette. The problem with a full sized oven is that it takes time to heat up, so people are hesitant to use it when they just want to heat up something quick for themselves. The toaster oven/air fryer makes oven cooking more convenient. It isn’t the alternative to the oven, it’s the alternative to the microwave, so your leftovers will actually have texture instead of being a soggy mess. I share a lot of your sentiment here about buying hoards of single use items. But I really put the instant pot and air fryer in a different category than, say, the vegetable juicer, electric can opener, or rolly pizza cutter.