[mkl]

Sanskrit has the big advantage for that purpose of being "dead" (not taught as a first language), so its existence is academic and pronunciation is relatively fixed through time; Latin would be similar, and its alphabet, this one we're typing, is a good phonetic representation. The pronunciation of "living" languages changes quite a bit.

Most languages with phonetic writing systems (alphabet, abugida, syllabary, etc., but not pure abjad [1]) have direct phonetic representations. English, French, and a few other European languages are unusual.

[1] https://en.wikipedia.org/wiki/Abjad

[prox]

Besides being dead as a reason for it being fixed, I think it might also reflect the high reliance on the oral transmission of texts (which your excellent examples I hadn’t heard about emphasize)

The name for learning (sacred) texts in Sanskrit is “shruti” , that which is heard. Sanskrit grammar did change over time, at least until Panini wrote down the rules around the 6th century bc.

[prox]

Also, something I just remembered, in vedic rituals there is actually a priest present who checks if the ritual and the sanskrit recitation is correct. This is also a reason we still have access to vedic sanskrit and we can be confident in its transmission accuracy afaik.