Uber India — late acceptance from drivers

Address:

Mumbai City, Maharashtra, 400033

Why does the app shows like in 2 mins and 3 mins away when the driver really comes after 20-25 minutes. This is completely #.
If anyone has a emergency and someone booked uber because it is 2-3 mins away but the driver comes in 20-25 mins then what is the use of immediate service.
Either the app should show real timings or the driver should really really improves at their acceptance.