In addition, certain words in one language, have absolutely no corresponding words in the other language, or they might have a more distinctive set of words for something expressed in only one nebulous word in the first language, so translators often have to make their best effort to estimate (guess) exactly what was being said in the first language, and possibly use a bunch of words in the second language to try to approximate to the best of their ability what they believe was probably meant by the first language.
There is also the problem of words changing very much over time. Even in English (from old English to new English), it is often very difficult to know exactly what the old English was saying, and the biblical texts were written a long time before that old English was written (and we do not have any experts from those biblical days to explain exactly what those Hebrew and Greek writings really mean today).
In addition to all that, translators always bring their own biases to their translation efforts, so if they are vague in their own mind about something, or not quite really sure, they likely err to the side favoring their own beliefs and prejudices when making uncertain choices.
You can look up the biblical Hebrew and Greek and individual words online, or in your own Hebrew or Greek Old and New Testaments and Dictionaries, but those online dictionaries were certainly not written by the Holy Spirit, and those various dictionaries often differ with each other as to the precise, exact meanings of different words, phrases, and sentences (and the printed dictionaries do likewise).
It is not a prudent or honest thing for anyone to stick their nose way up in the air, and try to brag that they looked up some Greek words in an online or printed Greek dictionary or interlinear translation (or other language study tool like that), and claim that they now know everything there is to know about a particular text, as that is quite simply never the truth, and anyone who believes it is, is just deluding himself or herself.
Whenever people trust themselves to be special recipients of the Holy Spirit's personal guidance, making their self- interpretation of the Holy Scriptures better than everyone else's "Holy-Spirit-guided" self-interpretation of those same Holy Scriptures, you end up with the folly we have today, with so many contradictory interpretations of every text in the Bible.
After praying for the Holy Spirit's interpretive guidance, William Miller, one of the founders of the Seventh-Day Adventist denomination, interpreted some scriptures in the books of Daniel and Revelation in the Bible, then declared that Jesus Christ was going to return to Earth in the "Clouds of Glory" in 1844.
He was wrong too.
As St. Peter said:
First of all you must understand this, that no prophecy of scripture is a matter of one’s own interpretation. 2 Peter 1:20
We can see that in the corruptions of scripture by the Catholic Church. You illustrate that in the verse you reference.
2 Peter 1:20 First of all you must understand this, that no prophecy of scripture is a matter of one’s own interpretation.
That's from a Catholic Bible. Now let's look at it from the Greek.
1 Peter 1:20 Above all, you must understand that no prophecy of Scripture came about by the prophet's own interpretation of things. 21 For prophecy never had its origin in the human will, but prophets, though human, spoke from God as they were carried along by the Holy Spirit.
That verse is not talking about man interpreting prophecy today. It's talking about how it was God who gave that prophecy and not just man's interpretation. The twisting by the Catholic Church to try to keep people from reading and understanding scripture is pervasive and insidious.