ICICI Bank app & Paytm stopped working on iOS 15, they require iOS 17 now. I suspect many more apps will follow this trend, except social media apps.
I guess it's time for users of following phones to upgrade.
iPhone 6s, 2015
6s Plus, 2015
SE 1st gen, 2015
7, 2016
7 Plus, 2016
8, 2017
8 Plus...