1. How much content are we talking about?
2. How many people use your server?
Yes, QuickSync is amazing but hard drives alone (for a larger collection) are incredibly expensive (today). Even before prices shot up I know people that sunk $8K+ into hard drives alone.
A single 20TB drive can hold quite a bit of media.
Not quite. Before the insane prices I was able to get 4x 20TB for $1,200, so $300/20TB, so $8000/300 = 26.6, call it 27 drives, so 27x20 = 540TB, a little over half a petabyte, not "petabytes" (before mirror/raid/etc).
If you were buying that over time and keeping your price-per-harddrive about the same, you'd come up with much lower (since you would have been buying smaller drives in the past. Also smaller/older drives have to be rotated out due to age/wear/too-small so it's not all additive.
But you are correct, there is a difference between "data hoarders" and people that pirate and it's an important distinction (eww, that sounds a little AI-y, but I wrote it).