Real wood is lovely in many ways, but it is an organic material that is prey to natural processes. It absorbs water, making it liable to rot and warp. It also fades. This can be an advantage, if you want a weathered look. But if you want to maintain colour in timber, it needs staining. This adds to the on-going maintenance needs, as wood should be stained every few years. With wood-effect porcelain paving you know the colour you lay is the colour that stays.