OMISSIONS or ADDITIONS?: Why Are Thousands of Variant Readings Missing from the Modern Bible Translations?

The Byzantine text family that makes up the Textus Receptus, which is behind the KJV and the NKJV is 80-85% in agreement with the Alexandrian text family that is behind almost all modern translations. The King James Version Onlyists (KJVOists) & the Textus Receptus Onlyists (TROists) call the differences omissions in the Wescott & Hort 1881 Greek New Testament (WH) and the Nestle-Aland 28th edition Greek New Testament (NA). They would argue that many of the differences are actually additions to the original texts, which has now been restored to its original form by removing spurious interpolations? Who is correct?