The screen saver was originally designed to prevent phosphor burn-in on CRT monitors. In the era of LCD and OLED screens, its function has pivoted primarily toward security (automatic locking) and power conservation. When a screen saver fails to launch after a designated period of inactivity, it suggests that the operating system is receiving input signals that reset the idle timer, or that system policy is preventing the initiation of the display process.
The most common reason a screen saver doesn't start is that it is set to "None" or isn't properly configured. why is my screen saver not working