It so happened that much of what has survived under the rubric "Hinduism" (itself an umbrella term for a whole gamut of philosophies, religious beliefs, rituals etc. and everything in between) has been through Sanskrit texts. It does not mean that all the concepts/ideas originated in that language domain. This is why you have the many schools of Hindu Philosophy categorized as orthodox (six recognized) vs. unorthodox (three recognized) and there are still more schools (notably many Tantric philosophies) not recognized under either of the above categories. Given the bewildering diversity of languages in the Indian Subcontinent it is almost certain that Sanskrit texts recast/reformulated philosophies/concepts/ideas from other languages (eg. Tamil and Sanskrit).

The situation is analogous to what happened after the Scientific Revolution where knowledge from German/French/Other European languages got disseminated via the English language through colonialism to the wider world.