Different artifacts disappear for different reasons, but when it comes to anything regarding the working class the reason is usually "they wore out". Clothes and furniture specifically have a tendency to get damaged through everyday use, and if there's nothing remarkable about them, why would you keep them? Broken-beyond-repair furniture is fuel for the fire, and clothes eventually become rags for cleaning. Even in centuries closer to our own, people did not tend to save clothing unless it was especially expensive or worn for a special occasion (like one' wedding).

Additionally, clothing does not last long in the ground outside of exceptional circumstances that protect it from decaying, and neither does wood. So when we have wooden or fabric artifacts from millennia ago, they've survived mainly due to their being high-status grave goods.