Opponents of the Authorised Version (KJV) have frequently complained that the English of the KJV is 17th century English and is therefore, obsolete. From here, the same opponents would insist that we need a modern English Bible today and may even compare KJV English to Latin.
However, KJV English is in reality Biblical English shaped by the original Hebrew and Greek of the Holy Scriptures. KJV English was not the everyday English spoken in 16th and 17th centuries England nor in any point of history.
William Tyndale's 16th century English translations form the foundation of the KJV. Even Tyndale, who would later become a martyr for translating the Scriptures into English and who also famously declared that he desired the ploughboy to understand the Scriptures, did not translate the Scriptures into the everyday English of 16th century England. To better translate the Scriptures, Tyndale even introduced words into the English language. Meanwhile, the KJV translators wisely kept the second person singular pronouns of thou, thee, and thy because the original Hebrew and Greek differentiate between the second person singular and plural. This was done despite second person singular pronouns were already going out of use in 1611. Therefore, the English of Tyndale's translation and of the KJV is the timeless and precious Biblical English, developed to accurately translate from the original Hebrew and Greek.
If the English we use when speaking to a respected teacher and a friend is different, should we not use a better English during worship to rightly express our reverence towards our Almighty and infinitely holy God? The 18th, 19th, and even early 20th centuries hymn writers understood this and this is why all their hymns are in Biblical English.
If KJV English is timeless and will never become obsolete, the cry from KJV opponents that 'KJV English is obsolete and we need a modern English Bible' is unreasonable.