English Translation
It is no use arguing about it.
Tip: むだ is often written as 無駄 in Kanji. But 無駄 is one of 当て字, which borrow the pronunciations from Kanji but there is no meaningful relationship between the Hiragana versions and the usages of Kanji.
This article, written by a proofreader of an established book publisher, explains the definition of 当て字 and when to avoid using them.