My rice cooker has different buttons for different kinds of rice (because they require different cooking times and temperature gradients), and rice porridge is quite nice for when you're sick -- I guess you thought I meant oat porridge in my original comment. And being able to have freshly-cooked rice at a fixed time (for breakfast or dinner) is super useful. I personally don't like congee (I didn't grow up with it), but my partner cooks it from time to time for herself. So we end up using most of the features pretty often.
But I guess whether you'd find those features useful really depends on how often you eat rice at home -- my partner is from south-east Asia so rice is part of basically every meal. When the rice cooker is empty, I fill it at night and set it to finish cooking in time for lunch the next day (if you just cooked it and left it overnight it wouldn't be as fluffy).
I don't use my rice cooker to bake cakes, but these kinds of features are born from the fact that in Japan very few households have full-sized ovens and so other appliances have to fill those needs.
But I guess whether you'd find those features useful really depends on how often you eat rice at home -- my partner is from south-east Asia so rice is part of basically every meal. When the rice cooker is empty, I fill it at night and set it to finish cooking in time for lunch the next day (if you just cooked it and left it overnight it wouldn't be as fluffy).
I don't use my rice cooker to bake cakes, but these kinds of features are born from the fact that in Japan very few households have full-sized ovens and so other appliances have to fill those needs.