why people live life which is so hard?

well because they have to earn money almost every single day, I mean they have to work and get up in the morning, which is hard work, and at the end all you got is little. Even going to college is hard work - spend time on stressful assignments and homework has a due date; facing exams. And even worse is that if you don't do this there is no else left for you to do, because the world works that way.

first it is hard to kill yourself. second nobody kills you directly even if they wanted becasue todays law prevents it. so you cant kill yourself, people dont kill you directly but make you miserable. and you only live once and dream that it get better but if its intorarable jumping off very very very high building might do the trick. or starve yourself to death, I heard that some models did that and died. btw why is life hard, i gotta study the buddhism to understand that.

Compared to countries x,y and z, it's heaven.

Because deep down people have doubt that there's heaven. So they live and hope to have kids etc.