The human body wasn't created to be at rest. It wasn't created not to be used. Our muscles and circulatory systems and respiratory systems thrive when they're used regularly, and we can keep our bodies in good shape only by using them regularly. Personally, I take every chance I can get to exercise my body. I park further away from stores so that I can walk across the parking lot, I take stairs instead of escalators and elevators, I carry my luggage instead of rolling it when it's not too heavy, and I do other such things when time and circumstances allow.
I don't believe that every labor-saving device that's out there is good for us. I don't believe that it's in our best interest to take advantage of every device that does things for us, such as walking. If we really want to live fully, we need to make sure that our bodies are in good working order. And the only way that we can keep them in good working order is by using them as much as we can in ways that are as healthy as possible.
That doesn't mean that anyone who takes an escalator is lazy or unmotivated or anything like that; what seems to be the case is that so few of us make conscious decisions based on what will be best for this body that's carrying us through this life--and if we start making decisions based on what's best for us, then we can start to enjoy healthier bodies that take us through life much more easily and effectively. And if we have fewer problems with our bodies, then we can focus on other things that are important in life, like helping others, spreading love and kindness, and being the people we simply were meant to be.