Depends on what is the definition of pain. Yes many times pain is necessary not just to survive but also to thrive. The way the world works, some pains are inevitable for many and quite important to learn the value of many things.
But there are different degrees of pains. Does having to face repeated setbacks and traumas in your life, to the point that it completely breaks your spirit,mind and body comes under the same category of pain that many people consider necessary? I doubt that.
Also,for many people one pain is stacked upon another without any relief which eventually render them helpless. For some people they can easily face such harsh pain,which are truly unbearable for others.
My personal opinion is that we all are different and we all have just one reality that we can truly live, i.e ours. There are so many other factors that determine how people turn out to be and how much they can cope. There is no need to compare and generalise difficulties and pain for all especially when it involves very little empathy and understanding. But it is a norm today.