One other not mentioned problem is the increasing trend to interconnect all grids into larger ones. Smaller independent power companies may not be as efficient, but not being connected to each other mean sthey are also isolated in case of some other disaster, so they can't all be knocked out at once by a random kamikaze squirrel on a line. IIRC, having delved into this subject some years ago, there are some transformers of quite large size, that are very, very rare, and no longer made in the US. The source for them now is either France or the Russian Republic. If these fry, for whatever reason, bad, bad juju.....