I have had a Zojirushi induction rice cooker for at least 9 years now, and it's not -just- a rice cooker- it makes all kinds of rice fabulous, as well as delicious porridge, potatoes, and even simple cakes like banana bread. I can do certain kinds of one-pot meals by successive layering of ingredients on top of the rice. It is NOT a fast cooker, but comparatively it is lower energy
consumption than stovetop. It has two timer setups, for when you want the dish finished. I originally invested in it when I went back to university, because I was able to set it up the night before for porridge, so we would have hot breakfast made for us at 6AM, and then after we ate I would wash out the bowl and set it up for dinner and use the second timer, so I would have dinner (Or at least a portion of it) ready for when I would get home at night. Still useful all these years later, and I use it at least a couple days a week.
This last winter (In November, specifically) I finally decided to replace my crockpot and traditional stovetop pressure cooker with an instant pot, after getting to test out my brother in law's appliance. The instantpot takes up space, but less space than the other two pots when combined, and does both functions. I particularly like it for beans! I've also processed quite a lot of apple
butter in it. It's nice for whole chickens, and okay to make soup. (rapid agitated boil on a stovetop is better to break down bones for richer soup, but this uses less energy and has easier cleanup).
For me, it doesn't replace the rice cooker, but neither did the crockpot or pressure cooker.