Also I don't think the global economy can afford 5 year lockdown, it will cause starvation among with other cause of death, which might end up 'killing' more than covid-19
I don't get the "starvation" point. As far as I know, nowhere in the world does "lockdown" mean "farmers aren't allowed to tend to their fields and animals". I live in Austria, which has been in "lockdown" for almost six weeks now. The shops are full of fresh food: Both food production and distribution are working exactly as before. There are non-staple foods where production is endangered -- asparagus and strawberries, I think -- because they depend on obscenely cheap foreign labor, which will now be flown in and given special exemptions. But even without that, we wouldn't starve without asparagus and strawberries.
Could you explain what kind of lockdown model you are thinking of that would prohibit production or distribution of food?
Worse thing is, starvation will be the lesser concern if it were to happen. People won't let themselves die of starvation, they will kill for food. Food scarcity will be nothing compared to the ensuing violence.
No idea why it would be 5 years. But a lockdown would not result in starvation. Why would it? We "only" lock down social life (bad enough with all kinds of negative impacts on people, society and economy), but the food supply won't brake down. Why would it? All necessary things will be kept open.
Worldwide, that's not to be taken for granted. Here in Russia, the police is sometimes stopping agricultural workers from planting their crops because of the lockdowns. (Source in Russian: https://www.kommersant.ru/doc/4311038)
I think the point was not that food distribution would fail, but that the more disadvantaged slice of the population would not have money to buy food anymore.
Could you explain what kind of lockdown model you are thinking of that would prohibit production or distribution of food?