> The cables seem to be mostly overground (at least in this video) and are probably easier to repair (oldschool infra ftw).

In Japan cables are (still) mostly overground. Use of underground is still a relatively new topic as addressed by the TEPCO website[1]. The first footer on the bottom of that page provides a nice TL;DR of the state of play:

     The plans for underground conversion have consisted of "Plan for Underground Conversion of Power Lines", which covered three terms from FY 1986 to FY 1998, followed by the "New Plan for Underground Conversion of Power Lines" from FY 1999 to FY 2003, and then the "Plan for the Removal of Utility Poles" from FY 2004 to FY 2008. Based on these plans, approximately 7,700 km of lines all across Japan were placed underground over 23 years by the end of FY 2008 (with TEPCO responsible for approximately 3,500 km).
     Currently, we are consulting with related personnel regarding items such as locations for conversion as based on the new "Guidelines for the Removal of Utility Poles" established in FY 2009.