Hi,
I have a few observations which I think will be helpful for you.
First of all, please focus on the question and notice that the question asks for advantages and disadvantages. You have talked about one disadvantage i.e. deteriorating health and one advantage i.e. professional growth. What this means is that you have not responded to the task completely.
Secondly, the conclusion does not answer the question whether there are more advantages or more disadvantages. It simply states what should be done- a new suggestion/idea. Because of this reason, your essay will get lower marks in cohesion and coherence as well as in task response.
Please also note that your first example is not completely relevant.
Example: around 70% of obesity comes from desk jobs
You are talking about desk jobs but not long hours. It is not necessary that all desk job holders spend long hours and only desk job holders are doing long hours.
You may reword the same example by saying: 70% white collar employees who work for more than 8 hours suffer from obesity.
I reckon this writing will get a 6 or 6.5. But this is just my personal opinion. If you tweak the writing a little then you can score more. All the best
Thank you very much for such a detailed feedback. I will improve and will submit another.