Apologies for replying to an old post... Yes, In India Uber drivers always call first. I think that

(a) they don't always know how to read and follow maps; one driver didn't know that the map could be enlarged with one's fingers for better detail. I don't know if Uber provides any training. In my experience Ola drivers were much better.

(b) Their customers are also inexperienced and may not check to see if their current location is being reported, so the drivers have to make sure they are going to the correct place.

As a result, using Uber in India with a foreign phone number is not the greatest idea.