I disagree, but only based on empirical evidence (and I have no idea how one could measure it scientifically without getting into an argument as to what defines happiness - Maslow?).

I've lived in third world, "second" world, and a host of first world countries including the very desirable Australia, Singapore and Switzerland and I've definitely found a strong correlation between wealth (including scientific and political) and happiness.

Past a certain level of personal wealth and regardless of the surroundings (although they affect that level), philosophy becomes more important, but that's another argument. Even there, I'd argue more prosperous countries are correlated with sounder philosophies and happier HNWIs, but my sample size is much smaller.