I don’t mind mowing my backyard; it’s small, level, and is more or less a rectangle.
My front yard is another story. Despite it being half the size, it’s on a hill — about 20 degrees — and in order to get to it, I have to carry a lawnmower up several steps. So it’s been with great relish that I’ve been able to test robot lawnmowers for the past few years. It’s certainly saved me time and aggravation.