Paper getting rejected from many journals after no proper review - What could be the problem?

I don't think there is only one reason for all the rejections you got. The first journal seemed to reject you because of a formality, which could have been prevented (abstracts usually never have citations). Maybe they think if you can't follow the submission guidelines to every last bit you don't deserve to be published (which can be unreasonable).

After that your research was already 14 months old. Did you do a new literature research? The novelty could have faded during that time. Journal 2's and 3's rejections seem legit and happened in a relatively reasonable time frame.

I guess journal 4's answer does look like the editor/referee didn't read it in detail. But before accusing them of lack of interest or ethics, you should ask yourself if your research has the quality and novelty to be published.

You also need to overthink your choice of journals. High-impact journals are often not the best choice for your research due to their high standards. They also tend to not publish very specialized articles.

My concrete advice: Review your article and try to improve it. Get criticism from colleagues and take it seriously. Compare your article to similar articles from your field and apply those same standards. Then choose a journal that is common in your field and that published articles related to your work and try there. Good luck!

In my opinion, journals #2, #3, and #4 tend to reinforce the same underlying problem with your paper. It appears that the main theme of your paper is now obsolete and of not much interest to the community. The journals are NOT interested because they think their readership is no longer interested in that topic.

Secondly, either your paper does not offer any significant improvement to existing techniques (just minor/cosmetic changes, or no motivation behind your variations) or you haven't done a good job in highlighting them.

As suggested above, get some help from outside (your lab) including, if possible, from outside India. At the very least, however, get advice from a respected researcher (e.g. someone with a few papers in that or similarly reputed journal). Perhaps you're over-estimating the quality or relevance or layout or contribution of your work.

Best of luck.

I have a different theory. When a reviewer meets with a paper that is unsound but cannot prove that it is unsound, they generally side step and find other mistakes to reject the paper. It takes a lot of work (at least several days) to find a solid proof that the method cannot provide the results demonstrated. Not many people have the time or will to do that. I have witnessed a paper rejected with proof to be accepted by another journal, for that, I cannot blame the reviewers.

To solve the issue, try to show many consistent results to convince reviewers that your results are not made up. A similar situation happened to me at the start of my PhD, the reviewers were a little more direct and helped me out to figure the issue. A two full-page of results taken from multiple images and a detailed verbal explanation of how the method works convinced them. Try the same.