When the IE family had been discovered and scholars sought the land of origin, they initially thought of India because of Sanskrit’s ancientness.

Beekes, R.S.P., 1990: Vergelijkende Taalwetenschap. Tussen Sanskriet en Nederlands, Het Spectrum, Utrecht. (Beekes 1990:73), quoted in Elst, Koenraad (2018). Still no trace of an Aryan invasion: A collection on Indo-European origins. Chapter:Why Linguistics necessarily holds the key to the solution of the Indo-European Homeland question