This is the flightwise route for COA48 today:

KEWR MERIT HFD PUT WITCH ALLEX.N79B.YQX.NATT.MALOT.NATT.GISTI LIFFY.UL975.WAL.UM16.DOLAS.UL603.BASNO.UL620.ARNEM.UP147.RKN.UL980.CZE.UL980.USTIL.UN191.SITBA.UN191.NM.UM991.TOKMU.UM991.OLGIN.B494.RISKA.R227.KZ.B450.OLMAT.R120.VABB/1404

When I saw this, I noticed that the route ends with an airway, and the last waypoint before the airway is OLMAT. OLMAT is located over the Caspian Sea and 1800 miles away from the destination. The airway, R120, does not lead to the destination. After further research, I've noticed that a lot of flights that go to India have the last chunks of their route chopped off.

What is the reasoning behind this?