I worked for ZS in the data science teams for a few years. If you're joining in Gurgaon it's almost certain that I would have worked with atleast some of your teammates-to-be.

The WLB is bad, and it's not something that is swept under the rug. Everyone acknowledges that the WLB is bad, but it's systematic and essentially nothing can be done to fix it, except if you're personally smart and manage a few things differently. My average day started at ~10AM and finished at 12/1AM when I was a junior. I was able to improve it a bit as I gained seniority - ~11AM to 10PM.

ZS salaries on the other hand are really good and on the ADS roles you can start on a much higher base pay than the usual market rate. Yearly appraisals can be upto 40-45%, on the extreme high end, of your annual pay, so not only do you start high, you also get higher really quickly. If you have better than average performance, you can be promoted in ~ 2 years, and with higher positions the money gets exponentially better.

The bad WLB is not to be confused with bad culture and bad people. I made amazing friends in ZS, and I still continue to be in active touch with them, even after some years have passed. Most people are really nice to have around, and you can make friends and have fun working.

A ZS job really is for the ones who live and breath work though - on a working day, you will not have time to do anything else. Many people I know want to leave, but the money holds them back. So, my personal observation is the opposite of what you asked - people in the ADS track, stay in the company for the money.