There is one more use case not covered by smartphones but actually covered by fixed-lens cameras - taking photos in rainy weather (which in some parts of the world is hard to avoid) or underwater. While there are waterproof smartphones, capacitive touchscreen becomes unusable as soon as it catches even a few drops of rain or water from wet fingers. A camera like Fujifilm XP140 works well in rain as long as there are no drops on the lens and under water if you want to make a shot of marine life.

And while there are gloves which allows to use touchscreen using it in the snow is not the best experience either - pressing a physical button is easier.

I expect many smartphones to have quality better then this camera but in some conditions it's hard/impossible to use a smartphone. And quality is enough to capture some moments from a family vocation.