Hot take
Recently Korea overtook Japan in GDP per capita. As a way to get some advantage I propose Japan to switch to Hangul
The new writing system would allow Japanese school children to free up many hundreds of hours from learning, and use that time for socialising and practical skills
The fate of the Kanji system can be similar to that of Hanja (Chinese characters in Korean) - slowly phased out and forgotten. I've heard a mention of Korean univercity students no longer being able to understand Hanja, and it's a recent development. After all, Chinese characters can be framed as a coloniser influence :)
The main reason to use Hangul over Kitakana/Hiragana is it's flexibility, as it's a proper composable syllable system. So anyone interested can read the text with just a small paper cheat sheet on hand
Personally, I've already started learning Hangul with the intent to use it for Japanese (on top of other things)
https://www.koreatimes.co.kr/economy/20250202/korea-overtakes-japan-in-per-capita-gdp-on-improved-trade-terms