Composites have some pluses, but also serious minuses. Here's a good overview: https://www.thebalancecareers.com/composite-materials-aircraft-structure-282777

Composites have some pluses, but also serious minuses. Here's a good overview: https://www.thebalancecareers.com/composite-materials-aircraft-structure-282777 https://www.thebalancecareers.com/composite-materials-aircra... Metals have inherent temperature-resistance and repairability that composites don't have, and support transsonic and supersonic flight heating. Some early aircraft that used composites ended up heavier than aluminum, so achieved no benefit. I consider metals to be higher tech than composites for aircraft construction. Also, metal can be quickly stamped, whereas composites are generally made by vacuum forming, which is a slow process that's hard to parallelize. Most of the WW2 planes you've heard of were made of metal in runs of 10,000 to 20,000 each, impossible for composites - you might get 10% or less.