I agree that it is difficult to compare.
Buying prices are likely to higher in Singapore than even the top cities in US, but if you look at rentals then it is a different story again. and if you buy your
property than it's not any more only a living cost item, but also a capital investment where you'd care more about increase in value. Like in Nordics, where I come from, you can basically get countryside or small town houses almost for free (say 60-80kEuros for 160-200m2 house) if you just take the burden of maintaining old properties (usually built in 60-70s). But I wouldn't compare those to Singapore, then in capitals prices for new properties are in pair to singapore, which is crazy for the size of cities we are talking about.
And though housing is often the largest single item, if you are eating out a lot, like more than 10 meals per week (pre-covid times of course) that can make a substantial difference too. It's a bit same Luckily Uber has made living/moving around without a car easier and cheaper in US.
If you check that numbeo site that SMS frequently shares, which to me look pretty realistic, main US cities look in many aspects same or more expensive than Singapore. I know it's an index, so everyone would have their own spending habits and living styles.