People often say/feel that suffering is good for you because it makes you appreciate what you have more.
For example: maybe you have a cold, and after it's over you think "gosh, I never appreciated breathing freely until now." Or: after a long period of poverty, you might look back and think "Now I appreciate having money, because previously I didn't have any."
But it seems highly unlikely that merely by accident we would all accumulate the optimal amount of suffering in the optimal distribution. We may be under-suffering in some ways and over-suffering in others.
Presumably, if you were over-suffering avoidably you would already be trying to reduce it. So the obvious room for improvement is to add more (targeted) suffering in our lives in ways that make us better overall.
But this raises lots of questions. For any given type of suffering, would it be better to suffer 10 mins per day, or one hour per week, or one week per year (e.g as a six-day bootcamp, with eight hours of suffering on each day?)
I suspect that small sufferings spread out across time are more helpful; that, for example, a 10 minute cold shower each day would make me feel more total gratitude for my cozy life than a one-week cold camping trip once per year – life is long and memory is short, so the cold trip would probably fade from memory after a week or two. But it's strangely hard to force myself to suffer, even if it's for my own good.