Good point!
One of the things that a lot of people have stressed here on this forum is to determine what works well you.
I would like to clarify that when I was getting those 750+ scores, I knew they weren't true reflection of my abilities. You are right that most of the questions were repeats after the 5th time particularly in verbal
Now here's what worked for me when i took the exams multiple times
1. I can say I almost did every question in GMAT prep software which is a great thing to do
2. I did not blindly select the answers even though I knew the answers. I tried working through most repeat questions that I saw (at least the tough ones). This was a really nice revision
3. I was pretty confident of my prep (although never thought of 770 even in my dreams

) and had done all my revision 3-4 days before the exam. I knew the exam content would never be an issue (believe me, the level of the actual test is not tough at all, it is just GMAT prep level). I knew that if I stayed calm I would be able to hit the 700 mark.
4. The last 3 attempts at the exam were on the last day where I just sat on the couch and clicked my way to 750+. Do not look at these repeated test attempts as a way to practice questions in test conditions. Look at it as a way to massage your ego a couple of days before the exam. Obviously, if you feel that you haven’t prepared well then no amount of ego massaging would work eventually
5. Getting 750+ a few times calmed my nerves and kept the negative thoughts away the night before the test
6. Maybe I overdid the GMATprep as I had too much time and did not want to practice any new questions. But I would certainly recommend that everyone do the GMATprep at least 4 times. In hindsight, trivializing GMATPrep really worked and seeing the white and blue screen did not scare me on the test day.
To stress the point again: I had worked very hard over two months which made me confident. I had also performed considerably well in the prep tests. So I had already reached the level I wanted to reach with respect to my prep. The repeated test attempts were for a different purpose entirely.
Hope that helps!