Wood-plastic composite decking (also called WPC decking) can be widely used, not only for indoor use, but also for outdoor use, and it can also be built and installed as an outdoor stair.
Learn more about composite deck stairs:https://unifloorwpc.com/composite-deck-stairs

There is no doubt that composite decking material is more expensive than wood. However, it is valued for its striking resemblance to natural wood and efficiency making it an excellent choice for decking. It is easier to clean and maintain which makes it last long enough to transfer the same value to the next homeowner.
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Link: https://unifloorwpc.com/composite-deck-stairs