They are cheaper and they pass IPXX requirements on dust/water protection easily. But they seem to be good enough because customers, despite some complaints, keep buying devices with capacitive buttons.
Also, mechanical stuff eventually wears out - at best with good quality ones, the product becomes obsolete before they do. For instance potentiometers [1] used for volume control on stereos rust over time and eventually become unusable. So there's a durability argument too.
In the case of cars, isn't it simply that there is no other option on the market?
Yes, now the cheap cooking stoves have touch interfaces which is an OBVIOUSLY bad idea, much worse even than touch buttons in cars. The expensive professional stoves however...
Expensive stoves also have touch screen, just with much better UX.
The touch buttons on my stove are easy to clean, but I think that's the only advantage.
> The expensive professional stoves however...
…have people whose job it is to clean everything every day anyway.