Hmm, I disagree. Vietnam was able to lock down. They're below average in GDP per capita. Their lockdowns were more effective than in any rich country and as a result they had a smaller economic impact.

Ultimately wether lockdowns can or can't be done is a question of governmental efficiency. In general, either the population is mostly rural in which case very little social contact is necessary for economic activity to continue, or the have a very urban population which means that they only need a smaller part of the population to work to make the country tick for a month or so.