* The proximity of power to population because it is a tiny city state. Singaporean governance is under extreme pressure to be effective because if it fails it cannot hide. This is a systemic issue that can be seen all around the world and is probably why some countries moved their capitals AWAY from population centres (e.g. brazil, myanmar): https://dash.harvard.edu/bitstream/handle/1/8830780/Campante...
* The reaction to the communists. Lee Kuan Yew didn't just annihilate the communists with coldstore, he tried to replicate their policies to maintain his stranglehold on power (note the resemblance of HDBs to soviet style housing, for instance). In a way, his lack of any real conviction and ruthless pragmatism helped here. This was echoed later when an opposition party set up on a platform of smaller class sizes. PAP effectively strangled the party (largely through unethical means) but then recognized the power of the protests that led to this party's popularity and took their policy (ceding no credit of course!).
* Lee's economic policies were, while good, largely not his idea. He had the good sense to follow this guy's proscriptions though https://en.wikipedia.org/wiki/Albert_Winsemius
I lived in Singapore for 3 years. While I acknowledge its success at industrializing, I hated working there. The authoritarianism and rigid class structure permeates every aspect of life. This also made it a really bad environment for tech to flourish IMHO, even though they threw money at it. Creativity is massively stifled. Cargo cultism of silicon valley was rife. Most tech startups and founder I encountered were fast followers and largely treated developers like cogs.