'Expand all' is a useful feature of the browser-based ClickUp, enabling seeing all subtasks at the same time, in a nicely idented view under each task. This is especially important when subtasks contain information that should be viewed every time a list is viewed. Please add ‘Expand all’ to the Mobile app.

Note: View subtasks separately is not the same at all - subtasks are listed at the bottom of the list, separate from their corresponding tasks. They are also not indented, so they look like tasks.