"Whoever told you that is lying to you"
White population decline is indisputably happening based on plainly observable statistics.
https://apl.wisc.edu/data-briefs/natural-decrease-18#:~:text=White%20deaths%20also%20exceeded%20white,National%20Center%20for%20Health%20Statistics.
https://thehill.com/homenews/race-politics/4138228-americas-white-majority-is-aging-out/#:~:text=By%202045%2C%20according%20to%20census,of%20the%20under%2D18%20population.