What they said only holds true because the growth continues so that the old volume of videos doesn't matter as much since there's so many more new ones each year compared to the previous year. So the question is more about whether or not it will hold true in the long term, not today
The framing here is really weird. The volume of videos increasing isn't 'growth.' Videos are inventory for Youtube. They're only good when people (without adblocks!) actually watch them.