Many rich people commit suicide because they don't have a goal in life, they start to get bored with their life, maybe because in difficult times they have their own targets, then when they become successful they start to get confused and don't know what else to do. so they commit suicide (this happens a lot in Japan).
I have not read or done any research about how many people commit suicide in Japan and why they do it, but I don't agree with what you said about people having no goal in life after one point. For me, this is impossible for a human to have no goals because a human will always be greedy by nature, no matter who it is, even those who say they aren't greedy for more things in life, lie to themselves, and deep inside, there is always something that they want.
Those who commit suicide are the ones who don't have any managerial abilities, they can't manage their problems in an effective way which leads them to try to run away from their problems and you can't do that as long as you are alive. If you have problems, you have to face them and solve them using your brain and understanding, and if you fail to do that, you will try a way to skip and for some people, that way is committing suicide which is absurd.
Someone with good managerial abilities would know how they should distribute their wealth and what things they should do if they don't have any personal desires. Millions of people need the basic necessities of life in all parts of the world. If you are rich and have nothing to do, go and help those people, you will get an activity to do and they will get some help. Killing yourself thinking that you have no goal in life is a lame thing, in my opinion.