Doing nothing is never a waste of time. That is if you are really doing nothing. Just sitting enjoying the thoughts in your own head. Resting your mind and body. Daydreaming? Not watching TV or swiping your phone. Just being alone with you.
Why isn’t this a waste of time? Your body and mind are getting needed rest. This non-activity clears your mind and gives it a reboot. The time can be used to problem solve by giving you space to think without pressure. Time for daydreaming and getting to know more about what you want and need to be happy. Time to just be you without any input from others. After doing nothing for awhile you will feel more rested, energized and there for you will be more productive.
Here is how to do it. Find a place away from others. A room inside is fine, but out in nature will have added benefits. My cat knows how to do it. Just find a cozy chair with a warm throw and curl up for a while. You might relax more with a cup of tea. Just sit a stare out the window. A few minutes or an hour to just sit and breath. Enjoy!