Then you have to consider that IC designs are usually easier to reuse since they're more flexible, if you can have a single design with different firmwares for your entire line of products vs custom hardware for every design. Even if you sell 700k units/year you probably have a few models in your inventory, each selling for a fraction of that.
Beyond that it's pretty common for modern appliances to come with so-called "smart" features that require more processing and more IO capabilities. It's not rare for modern coffee makers to come with a color screen instead of the good old 7 segment displays.
So really the equation is not that simple, especially for higher end models that will have a more expensive BoM overall and a lower number of units sold.