Cooking is one of the very few activities I know of where you are completely in your body and completely focused at the same time without it feeling like effort. When I am cooking I am not thinking about work or planning tomorrow or half-listening to a podcast. I am watching onions soften and smelling garlic and timing three things at once and it's completely absorbing in a way that most activities are not.
There's also something almost embarrassingly satisfying about making something with your hands that you can then eat. It's direct. The feedback is immediate. Nobody gives you a review or grades your performance. It either tastes good or it doesn't, and you know the second you taste it.
I have read things about how cooking connects you to your food, your culture, your body. Maybe that's true. For me it's a bit simpler than that. It's just one of the few hours of the day where my brain completely stops running in fifteen directions.
Yes, for me cooking is almost like a therapy.