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.
Growth in this context is that there are a larger volume of videos each year. So each year a single video is exponentially a smaller and smaller percentage of the total.
Growth in this context is that there are a larger volume of videos each year. So each year a single video is exponentially a smaller and smaller percentage of the total.