UN? Nuclear weapons?

https://www.thehindu.com/news/international/treaty-banning-nuclear-weapons-to-enter-into-force-un/article32939207.ece?

“Today is a victory for humanity, and a promise of a safer future,” Peter Maurer, president of the International Committee of the Red Cross (ICRC), said in a statement. An international treaty banning nuclear weapons has been ratified by a 50th country -- Honduras -- allowing it to enter into force after 90 days, a UN official said Saturday. 

What difference does it make? Which country used a nuke after WW2 or other than US? None. It's a taboo. There are more number of deaths recorded due to conventional warfare than nuclear warfare. And, there would be more number of civilians dead or misplaced than the number of soldiers died. So, what use is this if it's ratified? Does it change anything?

The clutch of nuclear-armed states, including the United States, Britain, France, China and Russia, have not signed the treaty.

UNSC countries didn't sign it. So, they don't care about it the same manner they don't care about other treaties or declarations. They already consider they are above such things, and this is just a platform to watch and enjoy.

The success of UN should be seen the way it has changed the way countries do things together and work towards a unified goal. Is that really apparent? Did UN save lives? It can't even enter a country unless the country gives permission. The UN was intended to reduce warfare between countries, but most conflicts after WW2 are intra-state conflict. So, the mandate of UN itself doesn't apply to current conflicts across the world. So, in such a scenario, is the UN even worth anything? 

Reforms in the UN? How does that happen? The countries just want to maintain status quo. No one knows the solution or doesn't want to implement it even if known. Just pass on to the next set of leaders.