What to make of the "Japanese solution" to boost private sector income?

In 2020, the United States and the euro zone (inter alia) will conduct a highly expansionary fiscal policy to try to prevent a decline in private sector income despite the decline in GDP caused by population confinement. This policy makes sense in 2020, because the private sector is forced to save more given the unavailability of goods and services caused by the decline in GDP due to the shutdown, and because governments can borrow this involuntary forced savings to finance the fiscal deficit. But after 2020 there will no longer be any shutdown, and the model that made sense in 2020 will no longer add up. It can be called the "Japanese model". The private sector has too much savings (in Japan, it is corporate savings due to the skewing of income distribution against employees), which weakens production (the decline in GDP is then a result of sluggish demand and not of the physical impossibility of producing as in 2020). The government borrows these savings to finance the perpetual fiscal deficit that stimulates demand, and the result is an endless rise in the public debt. It would be far better to stimulate private sector demand, for example through wage increases. So what we are see ing in 2020 (massive fiscal deficit financed by excess savings) makes sense because the problem is a decline in the supply of goods and services, but this would make no sense later in a situation of a shortfall in demand.