Boat builders understand that intangibles are important. Wood is pleasant to work with. Most or all other materials are unpleasant. Since recreational boat building is properly done for the pleasure of building, wood is a good choice. There are many more good plans for wood craft than for other materials.
Traditional designs are in wood.
These are proven designs. They are designed to take advantage of the properties of wood. Making them in other materials is possible but not always worth the effort. The bending properties of wood help build a vessel of good form. Wood is a fine building material in terms of strength and weight.