I can't innovate on furniture directly, but maybe on the design, manufacturing, and distribution processes around it. I have no idea how this industry is structured, but here are some ideas.

- Made to order furniture. Let users design their own, or at least mix and match high level componets at a finer detail than ikea.

- High end IKEA. Combine the flexibility of Ikea with high end designs and materials.

- High level office furnishing service. Companies provide a high level description of their furnishing problem, rather than choosing specific items. I'm sure these consultants already exist, but maybe it can be done in a more automated, scalable way.

- bid/ask interface for used furniture markets. This would enable sellers to passively sell items.

- used marketplace that uses ML to extract features from pics. I think this may already exist. Not sure.