There aren’t enough rare earth minerals on the earth to create the necessary equipment for solar, wind, etc to meet our current energy needs.
Even if he is wrong. Mining so many is very harmful. Much better off building nuclear plants. Along with some solar/wind/hydro of course.
The problem with taking long to build and expensive is easily solve if the governments build them. Currently in the US it doesn’t happen cause it’s left to private companies, and they take a long time to become profitable.