I think that in hindsight Sweden's approach will look reasonable. The data we have now, imperfect as it is, shows that the elderly are the main risk group and therefore the ones needing special protection. The South Koreans have very good data and publish it daily. Their recent CFR numbers by age group are:

80+ 17.51%

70-79 6.77%

60-69 1.74%

50-59 0.56%

40-49 0.08%

30-39 0.10%

0-29 0%

The data from other countries matches this distribution. Keep in mind that the CFR is what we have but not the number we want. The one we want is the infection fatality rate (IFR). This is the number of deaths divided the total number of cases (not just the reported ones). The IFR numbers are likely to be lower due to the fact that widespread testing is not in place in many countries.