The Instant Pot came on the market with perfect timing, just as the pressure cooker started to go from "geek" to "mainstream" in its adoption curve. The fawning press articles claim that it was Instant Pot that took pressure cooking from niche to mainstream, but I don't buy that -- I think it would have happened anyways. It's a good pressure cooker. A good stovetop one will be faster, but it's only significant if you…
Pressure cookers have been around for a long time: first manufactured in 1864 according to wikipedia (1). It's just that they have been out of fashion for few decades - possibly supplanted by the microwave oven in the 1970s and 80s.
So maybe the time was right for a better design to come back. The older designs had a reputation for very occasionally exploding, or the lid flying off and getting embedded in the ceiling. Not common, but it did happen and that puts people off.