As a more straightforward example, it's simpler to compare countries with closed pandemics - say Iceland or New Zealand. Iceland has much higher deaths per capita, but they didn't lock down nearly as hard (groups limited to 10, schools open for kids below age 10, etc.). If you do the math, Iceland lost about 120 extra years of life, or something like ~3 hours per person. Is depriving everyone of additional liberties for a month worth increasing life expectancy by 3 hours?
The case for France vs. Sweden is a bit more complex, since Sweden, even though it isn't locked down, will be "unsafe" for large numbers of people longer. The raw math and projection models suggests Sweden will lose an extra 1-2 days of life per person, but more analysis is needed to really understand benefits and costs.