Kazuma-sama
This is Kawaguchi Hidetoshi. This is my humble answer to the question.
Why were they born and are here, and why is it so painful and difficult to live...
I'm really wondering... so was my humble life.
To be honest, I don't get an answer right away, and I think it's still good to think that the answer won't come out that easily.
Also, even if an answer comes up, the question is whether it is actually the correct answer.
Furthermore, it is doubtful whether there is even a correct answer in the first place, and there is no single correct answer, and it can also be said that each has its own.
Anyway, it is certain that there is always a causal relationship (cause and condition) for “being born because you are born” or “living because you are alive”, of course.
There is no such thing in this world that would suddenly happen or perish without a cause or cause. All things and things in this world are made up of a myriad stream of causes and effects, even though they are complex.
Then, it was Shakyamuni who revealed one of the causes and relationships.
The most famous of these is the “twelve lucky signs” of “ignorance, action, wisdom, fame, six places, touch, receiving, love, taking, having, life, and death.”
The flow of hesitation and suffering is summarized into 12 items as a representative example, but those items are just large categories, and in reality they are more complicated, and originally, according to each person, elucidate that complicated flow so as to solve a puzzle, and prescriptions aimed at solving lost suffering are required for each person.
And, ultimately, it's up to you to resolve that problem. It's just that others are others, and even if you think about or compare other things, it's unavoidable, and it doesn't make much sense. Also, well, please think of others as others, and they are lost and suffering in the same way, large or small, due to ignorance (fundamental ignorance) and distress.
However, there are many teachings in Buddhism that serve as hints for solving these problems. Together with the above, it is called “Jitomyo, Dharma Light,” as Shakyamuni's will, and I would be grateful if you could continue to take an interest in Buddhism and proceed with your studies and practice.
Kawaguchi Hidetoshi Gassho