Monopod discussion - depends on what you shoot.
Shooting wildlife/birds/bugs/plants etc you do not have the luxury of sitting down, deciding your height off the ground, the orientation of your lens, etc.
You would also want to avoid any fixture that restricts or harms your mobility. It can be very very dangerous to both yourself and the equipment if you are walking around with a stretched out monopod. Tripping is the most common and try getting 911 to find you!!!
In the countryside - KEEP MOBILE.
Do carry one though if you have a backpack. Always useful in the right conditions but also as a weapon in case you need to chase off some pesky coyote, unleashed dog, etc. But a collapsible walking stick will serve the same purpose and be much much lighter.