Oh, don't get me wrong, everyone. The instantpot is absolutely 100% completely worthwhile. I hardly cook with anything else since I got mine in December. What I'm questioning is the utility of a pressure canner that will only do 4 quarts at a time – that wouldn't be a benefit to me, and I would recommend to the OP to buy the Instantpot instead.
Food is better and faster in the instantpot, mornings are less stressful because I don't have to set up the crock, etc, we're both more comfortable not leaving the house for hours with a crockpot going, and I get a lot done while supper is cooking because I don't have to babysit the stove. Also saving a lot of money on cooling because it releases virtually no heat into the house, and ditto for dehumidifying (a big deal here) because of the low volume of steam it produces. I'm also saving a great deal on yogurt over store bought. I never really got around to making yogurt before, but in the instantpot I can sterilize the jars and scald the milk at the same time, then just check temps once or twice as it's cooling down and incubate right there without shuffling everything around, I can also keep backup meals on hand in shelf stable form, throw in a few ingredients, push a button, and know we can eat in ten minutes. Our eating out/picking up takeout rate has plunged, and we're eating far fewer overprocessed grocery store frozen meals.