The UN is not a legislative body, nor the international law. It was designed to give countries a place to keep talking, and for other countries to voice their opinions on global affairs.

And sometimes large groups of countries coalesce around a subject and actually decide to do something about it (regardless of if the others agree).

And then in an even smaller set of circumstances the majority (or all) decide a situation warrants collective action.

But the bottom line seems to be you are correct in that countries pick and choose their stance on the UN resolutions. But at least they have an avenue to keep talking.