Japan debt/GDP is more than twice the US's.

https://economics.stackexchange.com/questions/11792/what-lev...

Not to say that it's okay, and Japan's economy certainly has issues with stagnation due to the debt load, but it's also not a "we have imminent hyperinflation" kind of thing either.

The concern with the past five months isn't so much the level of debt, it's the rate of change - we're increasing it faster than in the past... and this isn't a COVID-level crisis or a 2008-style deep recession either where Keynesian logic might make more sense.