I've found that a lot of apps prevent the system from sleeping. In some cases that's fine, but other times an app might be blocking sleep for no real reason. Sometimes I'd go to bed, only to find out the next morning that an app had been keeping my Mac awake the whole night. This is especially bad on OLED monitors, where the panel ages over time.
Some background utilities I keep running all the time often block system sleep, for no apparent reason. I find it frustrating that macOS lets any app silently tell the system to not sleep, and there's no easy way to see which app is doing it or to stop it. The only way I've found to see apps blocking sleep is through Activity Monitor or a terminal command, but neither provides a way to stop the app from blocking sleep without quitting the application.
MacRest runs in the background and catches any apps attempting to block sleep, and asks you for permission to block sleep. The first time an app tries to keep your Mac awake, you get a small notification to allow or block the app from preventing system sleep. From the settings, you can define apps that will always keep the system awake, choose which ones should never be able to prevent sleep, set custom sleep delays for power and on battery, and choose what system actions should prevent sleeping.
MacRest will automatically pause during media playback, calls, file transfers and updates, but everything can be customized through the app settings. There's also an option for a countdown before sleep.
Wish macOS did this itself! Sleep used to fail for no clear reason while some random app ran in the background. Now each one gets a quick allow or block choice.
DockFix