The first Korean Republic (1948-1960) was vastly more repressive than the PAP at its worst, let alone today. Mass arrests of political opponents, reeducation camps, massacres: you name it, Rhee did it. The second republic (1960 to 1961) was theoretically a liberal democracy, but got couped almost immediately. After that, South Korea remained a somewhat milder developmental dictatorship, ala Singapore, until 1987.

If they were less autocratic, and they still won elections, they’d do okay. The problem would be if they lost.

Japan was a de facto one party state for most of the post war period.