Not listed in the article but, starting around corona, price increases started happening all over the place. Russia's attack on Ukraine also caused price increases here for a number of reasons. Rice is now around double what it was a year ago (https://www3.nhk.or.jp/nhkworld/en/news/backstories/3949/ -- some general price increase, also shortages due to weather and shitty planning). The news keeps talking about price increases every month. Wages? Hardly budging. People are getting a lower quality of life for the same amount of work so of course the desire to put up with bullshit is dropping.
Now, if people would vote for anyone else, we might see something happen. Voter turnout is terrible in Japan. As a non-citizen, I can't vote so nothing I can do there. (Technically, there are some local elections that non-citizens can vote in (I think all requiring permanent residency permits) but nothing at an upper level).