Windows as tab groups. Some of those are quite persistent, but many are very transient and don't live longer than a dozen minutes. There are OSes with potent w

Windows as tab groups. Some of those are quite persistent, but many are very transient and don't live longer than a dozen minutes. There are OSes with potent window managers. Ideally tabs should even be part of the WM itself† and not be reinvented across each app††, or disappear altogether (e.g Chrome on Android, Exposé/Mission Control per app window grouping) † possibly even allowing tabs to be a mix of apps †† features such as pinned tabs, the defunct Firefox tab groups/overview, Vivaldi are especially egregious examples.