The reality is that Japan (and countries following a similar path) are strangling the younger generation by saddling them with generational debt. They become responsible for taking care of an older population, with no guarantee of their own future as their own ability to retire vanishes and income goes to zero. It should be no surprise that the older block also votes to protect itself, as politicians skew far older than the rest of the citizenry. The result of 'nature taking its course' is a complete collapse of the government. In the long term this is certainly a solution but not a particularly good one.
An argument could be made that a slow gradual decline would help ease these issues but you would need to convince people twice your age to willingly give up their benefits and things they worked for and were promised. What are the odds that you think that will work out?