> Can anyone share some insight?
If you were around in the 1980s, when Japan was at it's economic peak, Japan has slowly been passed by China and continues to tread water (i.e. stay in the same place, as China has passed it.)
Japan is a poorly performing economy in that there's been little to no growth since the bubble burst in the late 80s. Other economies have gone through growth stages and we had the Asian financial crisis and then the '08 global crash, but Japan has just kept the status quo. So from the perspective of economists, who expect growth, Japan does look bad.
In Japan, life is largely as it has been since the 90s. In fact with deflation, prices are largely the same as they have been for more than 2 decades. This is not a good thing mostly- healthy economies should have some small amount of inflation each year.
Hope this helps? (I am Japanese, fwiw.)