We also know that IPL has a really big effect on ICC itself. And BCCI gets really huge amount of money from IPL. But India does utilize the IPL really well to find some young talents and later make them world-class players. A lot of cricketers in the Indian national team have come from IPL. But with 10 teams, it is going to take really long for IPL to end this time. The international cricket schedule will also be affected by this as you said.
The irony is that no one can stop or question BCCI from extending the schedule of IPL. I don't know which world class players bcci has found though IPL. All good players in Indian side have come through there domestic cricket. If ipl has the capacity to produce world class players, India won't loss that badly in recent WC.