How will it really help Zebpay? First they need to revamp their exchange in India which also is not at all profitable considering that Indian market is too dry to actually catch some great profits.
Also, I think BAT rewards aren't profitable at all these days, especially with the price of each token down to just $0.18, even if you are able to collect 6-7 BATs after each month of surfing and browsing it generally translates to nothing, earlier when the price was high it could still mean some good 1-2k INR for you for free each month, also yes the KYC problem.
I cannot say how it will benefit Zebpay as I do not know anything about this exchange. I can confirm that this might be a strategy to add those users to the exchange userbase who were once earning a good amount every month using BAT tokens. They promote their browser using the incentive plan for those who use it for surfing. Other browsers do not offer such incentives, that is one hell of a marketing strategy.
Yes, you are correct BAT rewards are not profitable anymore. I went and checked the charts, and what I found is that the price of 1 BAT token reached its ATH in 2021 which was $1.45. It was the same time when Bitcoin was pumping resulting in multiple ATHs for Bitcoin. If someone still holds those monthly tokens to date they would get a good ROI when the next bull run starts.