I like the trend of invisible UI. It keeps the display free of clutter and persistent UI elements (hello, OLED) and doesn’t hinder usability at all. I hide scroll bars whenever possible because middle clicking is far more convenient than click-dragging. Hidden elements always appear by using a related action–moving the mouse reveals the play bar, scrolling reveals the scroll bar. It’s completely intuitive. I even remove the forward, backward and reload buttons on my browser because gestures and shortcuts are just faster.
UIs are near-universally as clean and functional as ever… at least on macOS. Windows appears to be a clusterfuck. Linux is alright.