I don’t think there is any reason.

You would be just happy to get any big4 job when you grad
KP only pay 20% when you get CA, so the first few years don’t matter at all, but by the time you reach senior associate and get CA, you just want to quit already. No one care about jumping from a big4 audit to KP audit

And of course everything comes down to opportunity. Everyone wants to apply KP but KP won’t hire everyone.