You seem to be making a case against wood as a material, and that can be assumed to be a case against heavier boards. Weight is just another design parameter,and it isn't the case that lighter is always better as we have been told for the past half a century.
On my last board, the 13-9 Dragon, my standard paulownia construction would have made the board at 35 pounds. I deliberately brought it up to 48 pounds and have previously ridden the same shape at 70 pounds.
The designs I use are able to take advantage of greater weight if desired. Mainstream 'Malibu' derived longboards are limited in that regard as they are very weight sensitive due to their unbalanced turning position.