You are missing one big difference.. Latin today is used solely for two purposes, as a liturgical language on religion, and scholarly study of the language.

Sanskrit has more than just those. There is literature like prose poetry and plays written, recited and enacted for crowds. There are philosophical discussions happening. There was recently a south Indian commercial movie released , made entirely in Sanskrit, for general public to watch and enjoy.

For these reasons. Sanskrit is not in same boat as Latin. People keep trying to push it in that, but it isn't.

Also, how a language changes along with time is entirely dependent on culture and the specific language construction itself.

Sanskrit was largely focused on oral traditions and was extensively worked out to prevent changes in language sounds. Paninis works shows how those time lasting standards and mechanisms were made and enacted. Due to its peculiar circumstances, it should not be judged on same standard as other language with little to no sound standards like in latin or Hebrew etc.