Singapore pays its public officials high salaries primarily to ensure the integrity and quality of its government. The official justification centers on attracting top talent who could otherwise command high incomes in the private sector, thereby establishing a "clean wage" that reduces the financial incentive for corruption. Salaries are explicitly benchmarked to the median income of the nation's highest earners.
This makes so much sense to me. If the public sector is compensated the same or slightly better than the public, then naturally we’d attract the best people to the public sector.
Personally I never considered a career in the public sector mostly because there is an expectation in my country (US) that I would be poorly compensated.
e.g.,
Singapore PM annual salary: ~$1.63 million USD
Singapore President salary: ~$1.14 million USD