If you are a Hindu, you would be hearing opinions of lots of “learned scholars” everyday, many people dealing carelessly with scriptures, and you are nothing but a helpless sheep who has to follow anyone of them, who can’t know your own scriptures because you didn’t learn Sanskrit.
(Of course, learning simple Sanskrit is not going to be of much help, still, you can relate to the words, and aspire to study more)
Now, Sanskrit is one of the oldest in the surviving Indo European languages. Learning Sanskrit makes it easy for you to relate and learn other Indo European languages, most important Indo Iranian languages and Farsi.
In India, there has been only one lingua franca for the whole. And that is Sanskrit. It still is Sanskrit. Your Hindustani water won’t boil in the South, esp in Kerala. For example, if you talk Sanskrit with certain gestures, you can survive in Kerala. But if you talk Hindustani or Urdu, even God can’t help you. Sorry. (Assuming you are that man who has least knowledge of English, or won’t deliberately speak it)
Check out the vocabulary of all languages of India. Anything common is clearly Sanskrit vocabulary. So, to thrive in India, you at least need to know basic Sanskrit vocabulary if not for the whole Sanskrit language. Lexical Sanskrit is the still the unattested lingua franca of India.