The countries that don't have our problems don't have our demographics, history, or size, or anything remotely similar. Most of them also (intentionally) have to pay much less for defense, handled by us, and thus have more free tax revenue to spend on social programs.
There are some problems which could be helped with better access to social welfare resources. Not all. Likely not most.
There are divisions in our society which are a result of our history likewise cultures which are quite separated to which there is not a simple solution or social program which can just fix it.