Paul penned that the saints (elect) were chosen by the Heavenly Father before the foundation of the world. Perhaps a word study as to what foundation of the world, really means, would set the time when and why some were chosen. Man has no collective or monetary say as to whom the saints are.. their tradition has no long term standing.
They might have been chosen but mere mortal Catholics got the sainthood on its path. Sainthood didn't grow out of the ground. Mere mortals had to propose it.
There USED to be a position in the Catholic Church called the "Devil's Advocate."
That position had the dubious position to point out whatever faults that the saint-to-be had. NO one was perfect and the Church had to decide if said saint-to-be would STILL be canonized.
Foundation of the world as we know it: I assume it meant the rise of homo sapiens.
If it weren't for the Church there would be no saints.
We are all saints and sinners...at one time or another.