Huh? Many US states legalized same-sex marriage before other Western democracies like France, New Zealand, Germany, etc. What exactly was slow?
France: 2013
New Zealand: 2013
United States: 2015
Germany: 2017
Other European nations began legalization as early as 2001.
Individual states, provinces, and cities might have acted sooner, but lets compare apples to apples.
An inordinate number of laws in the US are de facto “national” only because all States recognize similar laws, not because there is actually a national law. The Federal government doesn’t have the authority to enact most laws. It is the same reason the US does not have a national ID, why corporations are solely creatures of individual States, and why public health policy is decided by States (see: COVID).
New York (Population: 8.49 million): 2011
With populations like that, I think that is comparing apples to apples.
However, for the purpose of this discussion, we are talking about a society's relative tolerance of individuals choosing to live their life the way they wish and a relatively weak emphasis on social conformity.
I'm sure someone has done proper quantitative research on this, but offhand, I think the Netherlands would score pretty high.
P.S. I used "Western standards" to differentiate from developed Asian nations like Japan, Korea, and Singapore which are more conformist.
It's really not though.
By Western standards, America is a very conformist country. You can see this in how schoolchildren are required to pledge allegiance to the flag, to the slow acceptance of gay rights, to controversy over saying over "Happy Holidays."
I deeply wish America was a country that supported individualism in the sense of supporting and even celebrating the right to live your life as you see fit.
All too often, however, it seems that this love of "individualism" only surfaces when someone needs help or asks for cooperation.
That's not individualism. This simply selfishness.