Calling him "doing all things right" is a big stretch. The biggest error of him was to cling to power long after his mind went going.

Singapore's economic success was pretty much a meme too. The median income is only ~20000 USD a year, less than half of the economic product per capita.

There were three epochs in Singapore's economy:

First - everybody sat in their campungs and chewed paan. Pretty much nothing was happening till seventies. The only exception to that was that there was pretty much a small scale communist insurgency going on.

Second - reformation and industrialisation. This is the fabled Singaporean miracle. They built MDB flats, and everybody got so happy. A small industrial sector appeared, but it was quickly overshadowed by another kind of activity.

Singapore exploited Western reprehension dealing with Asia, and marketed itself as a "Western outpost" in the middle of barbarian lands. Singaporean companies used Singapore's GATT membership to run trade agencies that bought cheap goods from Asia, and stamp "made in Singapore" on them. That brought the country a big part of its current wealth.

Third - wind down and stagnation. China accessed to WTO, and Singapore's WTO membership no longer meant anything anymore. Singapore got into the middle income trap. People began to feel that Sing's economy was a one trick pony. It tried, but failed to upgrade its economy towards advanced economic activities. From that era, we got the fabulous Nanyang University, excellent primary education, and, back then, liberal immigration policy.

But there was blessing in a curse - China's WTO accession brought tons of money from China's first generation of billionaires to the country. From then on, Singapore fully took on its current identity of the "Luxembourg of Asia."