I'm not at all convinced. I was in peak physical condition while training for mountain races this year, and I still experienced the same stress and anxiety everyone else did.
I definitely notice a positive difference when I drink more water than coffee but the core problems causing burnout are still there and unresolved. It's a boost not a fix.
I'm convinced that a large part of the stress people have been feeling this past year is due to dehydration and lack of proper nutrition.