If you had really suffered maybe you would know why, but no man can know the suffering of another man unless he has walked a mile in his moccasins.
Maybe suffering is a deal-breaker because believers insist that God has all these attributes that do not comport with what logical people see in the world. If people could just believe that God exists without accepting all the baggage that goes along with that belief, maybe more people could believe in God.
I agree. No one can truly assess the extent to which another has suffered. Subjectively we could underestimate or overestimate our personal suffering. No one knows for sure except God, if He exists and is truly All-Knowing and Omniscient.
One of my work roles currently is assessing incapacity insurance claims for those who have experienced childhood sexual abuse. Some have experienced sexual abuse from a close family relative such as a father, brother, uncle or cousin over an extended period of time. There may be a mother who is oblivious to their daughter's problems and can not concieve that such abominable behaviour is taking place by a trusted family member within the security of the home environment. There may be drug and alcohol abuse in the mix. Severe psychological problems may render a parent unable to do much more than provide a roof over their child's head and meet their physical needs if that.
I've come across refugees from countries who have experienced persecution and their lives have been threatened over a sustained period. They may have witnessed or experienced physical assault, the loss of their livelihood and property, or even the murder of loved ones. The Prophet Baha'u'llah whom I follow endured torture, imprisonment, extreme loss and deprivation and exile for that He believed.
There are many on this planet who could never experience the time and luxury to have the conversation we can have. They may not have the material means to access the internet, may be illiterate and in such dire circumstances they consider themselves fortunate if they have enough to eat on any given day.
Of these people who have experienced dire and sustained adversity over extended periods, many are theists and find meaning and solace in their faith.
I agree with you though. Just because a person speaks little of their suffering, does not mean they have suffered little. Just because a person speaks a great deal of their suffering does not mean their suffering exceeds that of others. Only God knows our hearts and what we have truly endured.