Smartphones started from scratch supporting displaying the same content on displays with various sizes and DPIs. Computer apps and window managers were long stu

Smartphones started from scratch supporting displaying the same content on displays with various sizes and DPIs. Computer apps and window managers were long stuck with bitmap / pixel perfect UI frameworks. There was little to no demand for displays above HD before Apple gave devs the incentives to make their apps support HiDPI by introducing retina displays. Windows took really long time to offer similar support. Linux was (is?) waiting for Wayland to solve this issue.