There are two basic philosophies of translation, with a spectrum running between them.
I grew up with a very literal translation almost exclusively, it tried to translate word for word as closely as possible. Nothing wrong with that and it’s in many ways very useful.
The other is a free translation, by which the translator tries to get across the idea he believes the writer had in mind, but using words that a modern English-speaker would use.
I go back and forth between them, because I think they complement each other very well.
I also like the Amplified Bible, which brings in all the shades of meaning of words for which the other two methods have to pick one.
I’m with you. But one of the problems I have with the KJV is stuff like “In my fathers house are many mansions.” That is a TERRIBLE translation of the original Greek. It would be like translating the Greek word for “car” as “Limousine”. The translators inferred meaning that was not there.
Also, you’ll notice that some parts of the KJV come from manuscripts different from those sourced for NIV and others. You notice it when looking at the lexicon. Not often, but it happens. This is where I try to look at both versions. But the bottom line is that I mostly treat the KJV as though it was a Gutenberg bible. i.e. not in a language I’m fluent in.