The tidy round numbers come from the uncertainty of the datation method. It makes no sense to say, e.g. that they are 32049 years old when the dates are accurat

The tidy round numbers come from the uncertainty of the datation method. It makes no sense to say, e.g. that they are 32049 years old when the dates are accurate to, say, 2000 years. The fact that uncertainty is usually not properly reported is a tragedy in the scientific literature, and unfortunate in vulgarisation.