Hi HappyFeet and thanks for this essay.
Just from looking at it the reader can see that Tnduong is right - your first body paragraph is too short. You have a lot of examples in the second para in the body, but only one idea in the first body paragraph. Basically, you have only one idea - older people are wise/have a lot of experience.
Tnduong suggests adding some things that older people don't do - e.g. commit crimes, race through the streets, IELTS exams, etc....good suggestions!
Good Topic Sentence
I really like this topic sentence from Paragraph 3 (the second body para):
On the other hand, this greying population can also be detrimental to the society as a whole with its effect on healthcare, labor market, economic productivity and taxation.
The sentence is error-free and a perfect summary of the paragraph that follows. Well done!
- Equilibrium should be meet at a point → equilibrium should be met/maintained/kept at a point /found
The last sentence ( a 45-word monster) has got some very ambitious punctuation. How long did you spend writing it?
It is of utmost importance that an equilibrium should be meet at a point where there would be sufficient number of young people to replace the elderly and to keep the society economical, productive; in a symbiotic relationship where each would benefit from each other.
Here's a simpler rewrite in two sentences, with fewer words (30 total, 15 average sentence length), and with simpler punctuation:
Ideally we would have enough young people to replace the elderly and to keep the society productive, vibrant and well-funded. In this symbiotic relationship, each would benefit from the other.
In summary, there's some very good writing, but make sure you look at both sides. Have a look at the descriptors for IELTS Task 2 Writing under Task Response: I am sure you are aiming a something higher than Band 6:
"addresses all parts of the task although some parts may be more fully covered than others"