Don't you want to appreciate the book at its best, as it was appreciated by readers who read it in its original language? Why demand a compromised work? If you want to soak up untranslated idioms, you can just learn another language.
I think it’s a trade off then. I’d prefer authenticity, richness and nuance over accessibility. It is just preference. Did you prefer the modern accessible versions of Shakespeare or the originals in their Elizabethan glory?
Lol Just learn many other languages and cultural idioms that are sometimes regional and dense with meaning?
Also, as I mentioned, some idioms have regional meaning which raises the complexity greatly
Second, Learning a language is not a binary variable. It takes decades to master a language.
Finally, Your ability to appreciate a book is both a function of the text and your ability to comprehend the text. A translated book will give you better experience than the book in a language you are unfamiliar with.