Fusions op:
Let's say it's true, that after long enough meditation depression and stuff will disappear:
Something to consider: A body (in the sense of the organic processes which make up a living human being) can get hurt or become sick. A mind (in the sense of the psychological and emotional processes which make up a living human being) can get hurt or become sick.
Enlightenment is not a khandha that gets added to all the khandhas already in the mix that makes up a living human being.
Enlightenment is not a special link in the sequence of dependent arising.
Many people report improvements that co-incide with realizations. That does not imply causality.
If you get sick, get help. If you have pneumonia, while you still can do breath meditation, it is skillful to get the pneumonia treated. If you have depression, while you can still meditate, it is skillful to get assistance with dealing with the depression.
You don't get any extra points for neglecting your bodily or mental or emotional health.
Why does life/the universe/god only give us a life without depression/suffering after long enough practise, why can't we be happy to begin with and let it stay that way? Just a side question for the topic
Not just a side question. You just formulated the four noble truths in your own words, as a question.
Do you think this question is answerable? If there were an answer that was not a re-statement of the question, what do you expect to happen if you knew it?
Cheers,
Florian