Welcome!
A question similar to this was asked on the Estonian forum several years ago:
How to learn the cases historically. Really only the first couple of posts there were on this topic, though, so I'll post part of it here. Basically the thing is that while knowing historical forms can explain the modern ones, they're usually really not any easier to learn. I suspect the same would be true of other languages.
The exception might be if you want to learn several languages in a language family, then learning the ancestor language that they descended from might help with learning all of them, because you could see how each language developed out of that parent language, and compare languages to each other.
This was the question I mentioned above:
I've read quite often that once you know the historical development of the Estonian language (or perhaps if you know Finnish? ) the apparent irregularity on the formation of the genitive and partitive becomes self-evident. You learn how the patterns that once we regular started to look irregular thanks to the deletion of, say, a consonant that may even reappear in other forms. How much truth is there in this that can be used for practical learning?
And one of probably the most relevant answers there:
After I started learning Finnish, I realized how similar the two languages actually are and how it could be traced back how the seemingly random and irregular forms in Estonian actually came to be -- as Standard Finnish is much closer to Proto-Finnic, than Estonian is.
But, as fun as it is, I doubt this would be very helpful for learning Estonian. Besides these regular changes, there are also quite an amount of random stuff in Estonian
and things can originate from various dialects. Words from South-Estonian dialects could be especially different, because North-Estonian and South-Estonian are actually more distant relatives than North-Estonian and Finnish are.
My guess is the same sort of issues would be likely to be true in other languages, to a greater or lesser extent depending on the language, but likely to be somewhat of an issue. Loanwords and other influences from other languages would also be an issue, for example.