one reason which come to mind is Stream-ability.
if you download the video and play it, it might be fine. but users normally want to stream it.
to stream it, the endpoint from where you stream it needs to be near you.
if you are in the US and will stream something from a European server, you'll have problems. and even if you don't, that cannot be considered the norm.
that's why people use CDNs, and they are a huge business.
so there's an advantage to have a close to you instance, which has as much locally present content as possible
You broke and reinforced relativity at the same time