All things in moderation.
Young children, for instance, can suffer terrible emotional distress when they do not get their way. One can be compassionate for that suffering while recognising they must go through it to learn and grow.
If suffering is the gap between our expectations and reality, necessary suffering is the amount required to calibrate our expectations sufficiently accurately.
I don't think anyone argues that terrible suffering you described is a good thing, but rather that suffering is endemic to living. We don't get to decide how much happens to us, but we can work towards a world that minimizes avoidable extreme pain and injustice.
But there's also suffering caused by things other than people: earthquakes, volcano eruptions...
I don't know if this is always true, but it does appear quite true that we spend a great deal more time worrying about misfortunes past and present than actually experiencing them as they happen.
There are people in this world who live short, unhappy lives entirely as a consequence of things outside their control. Even worse, there are people who live long unhappy lives, again outside their control.
No point of view that argues it's their own fault for wanting things to be otherwise, or that suffering is necessary for joy to exist, is ever going to be satisfying to me.
The modern notion that life is supposed to be in a certain way is a big factor. There's a narrative that we' supposed to get married in our twenties, have kids, retire after a long career (a journey ending in management), then die of a heart attack at 72.
A lot of people torment themselves by telling themselves that this is what their life should be.
I think in this conversation we are conflating frustration ("my life isn't the way I would like") with suffering ("my child was ran over by a truck, I have brain cancer, my brother is dying of hunger in a ditch somewhere, I was tortured in a concentration camp, an earthquake killed everyone I loved"). The latter has little, if anything, to do with modern expectations of life. This kind of suffering has no greater meaning and is not necessary at all for joy to exist.
> The modern notion that life is supposed to be in a certain way is a big factor
The ancient Greeks and even older civilizations had all sort of expectations about how life should be. I don't buy at all that suffering is somehow the result of modern expectations.
We created some new forms of suffering and got rid of some older forms. And yet other forms are permanent, outside our control.
Did you begin to suffer from these things when they happened, or when you were told they had happened? If, later, someone came and told you it was a mistake, it was someone else that had suffered all these misfortunes, wouldn't you at that point stop suffering?
If this is true, how can it be that these events in themselves are causing you to suffer?
Good luck telling the parent of a child who died horribly "were you suffering before the doctors told you, or were the doctors themselves the cause of your suffering?".
I've no patience for this.
Pain, disease, death, grief, injury, etc. are all real.
It is usefull to calibrate the subjective to be as close as possible to the objective so that we do not inflict additional suffering on ourselves on top of the objective suffering already there.
Callibrating the subjective to ignore the objective suffering, to just want things to be the way they already are, is harmful because it causes more future exposure to objective suffering.
This view is summarized in the doctrine of the two arrows [1]. When asked if he still felt pain, the Buddha said he was struck by the first arrow called pain, but not by the second arrow called suffering.
It's most obvious when watching kids deal with the world—oh my god, the suffering they subject themselves to for little or no actual reason is incredible, and they find it so hard to get out of the habit of harming themselves in that way—but most adults do the same thing all the time, too.