Metal aircraft require 10000’s of rivets, and it is hard getting compound curves.
“Traditional” Composite requires wet lay and can cause an allergic reaction.
Carbon composite is an alternative to both. My MCR 01 has about 1./2 L of resin all in. You can cut and trim Carbon very easily with a Dremal, but you must use a mask and vacuum up the dust after. It has the advantages of Metal in that it is a good conductor for electrical purposes. Add to all this the fact that it is much lighter for the same strength, and you have the best compromise. The down side, it is quite expensive, but an MCR 01 VLA will cruse at 155kn on 100hp, and a typical Vans will need 160 hp Lyk costing £8k more and with 7 GPH fuel burn against 3.5 for the Rotax 912.
Rod1