The best way to improve mental performance, is to improve physical performance
World barista champions use the AeroPress to make coffee on the folding tray tables of airplanes.
Requiring a lot of time does not make a task important.
Food became for me a way of becoming self-sufficient with my hands, to regain manual literacy, which I think has been lost on our generation and certainly younger generations. Very few people can actually make things with their hands and do things with their hands.
I think willpower is very valuable.
It is predicated on the assumption that you dislike what you are doing during the most physically capable years of your life. This is a nonstarter—nothing can justify that sacrifice.