Why are there so many Bible translations?
There are multiple reasons for this, there are two separate texts for the New Testament, the one that is used by the King James and New King James has thousands of copies that match or near match, there is another set of texts used by most modern translations like the NIV. The NIV Greek text is dated as older, but is based off only two copies to my knowledge the textus sinaticus and the textus vatinacus, both contain heavy ommissions, the people on the NIV board thought these texts were better because they are dated as older, but an older copy of something does not necessarily make it better. That is why when you read the NIV it is missing some verses.
I actually grew up on the NIV, I sometimes quote scriptures from the NIV, but now I use the NKJV as in my humble opinion it is more literal and the texts for the New Testament are much better. If you get a NKJV Bible that has footnotes you will notice a ton of scripture notes that say something like NU-TEXT omits the word abcd, that shows you the omissions of the relatively small copies used by the modern translations.
Another reason for so many translations is money, everything except the King James Version to my knowledge is copyrighted and if you want to print a version of that Bible you need permission from the original publisher.
Another reason for so many translations is who sits on the translation board. Imagine four different boards, one board is Catholic, another Baptist, another Seventh-day Adventist, another some other denomination, are their interpretations of verses going to be different and affect the way verses are translated? Of course.