The industry has been chasing the seamless interface for two decades. We have largely won. Everything slides, fades, and confirms.
And yet the products people remember are the ones with edges. The keyboard shortcut you had to learn. The empty state that asked a real question.
Friction, deployed with care, is a form of respect. It says: this is worth a moment of your attention.
Smoothness is the default. Texture is the choice.