There are two interface design guidelines that are not mutually exclusive; a good interface should be general and a good interface should do one thing well.
A kitchen knife is general and does one thing well. It can cut all sorts of foods and it does it without issue. You can cut food in any sort of way, diced, thin, and so forth.
A banana dicer does one thing well; dices bananas, but it is not general. You do not want a kitchen filled with these type of tools, they take up space and require knowing many more interfaces than a good kitchen knife.
Code interfaces are no different.