I think we should distinguish between restrictions within a country and restrictions between countries
Restrictions within a country are, in democracies, up to the government and its charter with the people. There is indeed a balance between death and the economy
However restrictions between countries in the main only effect aviation and tourism. Goods and livestock can be imported and exported but the borders closed to humans. The economic effect would be limited and IMHO far less than the damage from a second, third or fourth wave. A vaccine is now possible at the end of 2020 and I just dont see the justification with killing the same number of citizens again.