Say, Czech Republic, has a similar budget and a similar population.
Yes, PPP will be different, but, as I said, running a country is different from running a city.
P. S.: Here's more detail:
Sweden is very close to the US by PPP (https://data.oecd.org/conversion/purchasing-power-parities-p...), it's population is similar to that of NYC (around 10 million) and it's budget is 1 trln SEK, which is roughly $100 bn, so the same amount per capita as NYC.
The point I'm trying to make?
It's not about money.
New York City has enough money to provide its citizens with all the amenities Swedes have, including free healthcare, free child care and pensions. They don't have to tax the rich. They don't need more austerity. They just have to use the money wisely.
Then if we take New York State budget into account, we'll realize this is sufficient to provide all New Yorkers with one more free healthcare, one more free child care and one more pension.