1914 is needed because that is what ties Nathan's prophesy to David about his seed being kings to time indefinite leading to jesus being king. But Jesus lived and died and did not become king. What gives? Did the prophesy fail?
No. Dan 4 tells us of 7 times or 2520 years that will pass when the kingdom was paused.
That started in 607 when the king lost sovereignty. That ended in 1914 with Jesus being installed as king.
Simple as that.