Banking is a long term business and Banker will be the key show man as seen clearly in case of HDFC Bank,Kotak Bank…
The examples quoted here like PhonePe, Paytm, I am curious to see the CF’s/profits to study if the models sustain in long run. I see lot of criticism by Walmart shareholders when Walmart acquired Flipcart which had -ve CF’s. Let’s see how the future turns out to be for the new age fintech firms and also the expensive buyouts by bigger gaints. AS RJ always says, in the long run the businesses are valued based on steady CF’s and predictability of the same over a long period of time( Same is seen in few FAANG Stocks( Face book, Apple, Amazon, Netflix, Google) ).
Coming to Ant Financial by Jack Ma if I understand correctly, the book is for MSME loans and not retail atleast from what I read. Disruptions are possible and retail investors can catch up in the listed space and also get lucky by having a good management over a really really long period of time. Having said that, HDFC twins are known for quality and at any day there would be buyers for them at a premium as long as the book has good risk, growth is evident, management walks the talk. RBI has certified officially more than once that HDFC Bank, ICICI Bank, SBI have grown so big they are too big to fail. HDFC Bank is probably the highly valued bank in the world 
Mr Market is Supreme, Price Discovery will happen eventually( - ve / +ve ) and going by history not to forget expensive stocks could remain expensive.
-If you are looking for Internet Companies in listed space, Check out Infoedge as case study.
<<No recommendations from me, Just my views after reading the communication in this thread>>.