Our denial of our needs (and to be clear, needs, not wants) does not create a more just world. Food, shelter, safety and caring relationships are necessary to all.
We require physical rest, emotional connections, daydreaming, food, laughter, purpose. And all of these things prevent us from fitting neatly into a machine model.
Self-care is so simple it can also be simple to forget. If you need time to put down work and check out from life, then take it. Know that you are restoring your energy for the challenges of life.