Quoting from article:
What scientists don't know yet is how 46 chromosomes came to win out over 48.
There is almost certainly no advantage in how the DNA is packaged. If anything, having a different number of chromosomes hurts someone in terms of having the most babies possible.
It might be that where the two chromosomes fused together, some new helpful gene was created. Unfortunately, there is no evidence to support this.
An alternative is that dumb luck allowed the 46 chromosome humans to win.
Is there some sort of weak correlation between the lifespan of a species and its number of chromosome?
And is it possibly the reason why 46-chromosome human ancestors prevailed over 48-chromosome human ancestors?
(I am no biologist; these are probably stupid questions.)