The accompanying 1993 article for those who haven't seen it previously: https://www.wired.com/1993/04/gibson-2/

Firstly the fact that the leaders and all the population are squashed up against one another exerts a massive influence on the government. They're much more vulnerable to protest than other governments because they can't hide as easily. This makes them much more nervous and more willing to placate the populace than the government in, say, Myanmar, is.

Secondly they were competing with as well as trying to crush the communist Party. LKY co-opted a lot of their policies as well as trying to crush them. Note the essentially Soviet style housing and various effective social security systems. These were popular. This is a pattern that they have followed since (crush the opposition, steal their policies) and it helped fix their schooling system by bringing down class sizes in the 90s. Is that democracy? Kind of.

Singapore isn't proof that if you get the right dictator he can be benevolent. It's proof that the will of the people can be exerted through means other than the ballot box and that even a thug can do the right thing if he lives in fear.