It looks more and more likely that the reason hardware has stayed so strong in Japan compared to the rest of the world is because of people from all over the world importing from Japan due to the weak yen.
Right now I can buy the Japan version of Mario Oled, Zelda Oled, Neon Oled in Amazon.mx for less than $250 usd not through a reseller but through Amazon themselves, they even offer monthly payments (up to 12 months without interest).
If I were to get it from Amazon.jp I would get it for aprox. The same price but without the option for monthly payments.
So no, software remaining that strong in Japan is just because Japanese people really buy a lot of software (software is also cheaper from Japan here but not to the extent of hardware and some games don’t support other languages so I guess it’s not as common)