OnePlus created Zen mode to help individuals in living without their phones so they could focus and practise meditation in a peaceful environment.
This is a more advanced version of the Do not disturb mode, so to speak. which will keep you from becoming distracted and responding calmly.
The OxygenOS 13 Zen mode features a theme to help you discover inner calm, and if we exclude everything, then the Zen Mode aids in battery conservation by decreasing screen time.
while working or living a non-technological life. The Zen mode in OxygenOS 13 will be more user-friendly and superior than early versions.