The article says that we sample random values by walking on a grid. But doesn't it mean that this way the values that we draw will be close to each other? For

The article says that we sample random values by walking on a grid. But doesn't it mean that this way the values that we draw will be close to each other? For example, if we have a 2-dimensional grid of size 1000x1000 and make 10 steps, all the values will be close to each other. Doesn't look like a good random sample. Knowledgable people, please explain.