Comment by rdw

The early generations worked as you describe. Newer/better ones attempt to map out the layout of the home, which allows them to cover larger areas, return to base to recharge/dump dirt, and to only gently touch objects instead of slamming into them at full speed. They actually probably still don't need ML for all of that, motion planning was able to avoid the need for "learning" for decades. But I bet they do use ML anyway.