Is it possible to implement a mobile application without using Activity components?

In Android applications, it is traditionally built around Activity components, which are responsible for displaying the UI and interacting with the user. However, technically, it is possible to implement an application without using Activities, for example, by using only Service or Fragment in conjunction with other components, or by creating an application based on the Jetpack Compose library with direct use of WindowManager.

But in practice, completely abandoning Activities is difficult, as they are the entry point for the UI and manage the lifecycle of screens. In newer approaches, such as with Jetpack Compose and the Navigation Component, Activities can serve merely as containers, with all UI logic implemented in Composable functions.

Thus, it is possible to minimize the role of Activities, but completely doing without them in a standard Android application is challenging.