Housing grants a significant advantage to solo players and fcs. Many materials can only be gotten through fc airship missions and many useful plants (including the thavnairian onion) can only be gotten from cross planting. I have literally made millions just from gardening.

We can argue all we like about whether it's a major feature or not. But there is no denying the monetary advantage a player/fc can have when they use their house to its full capabilities. Housing is not only cosmetic.