VPN has absolutely nothing to do with hosting a video platform, no clue why you even bring it up.
Debrids is just a file download service, isn’t it? But even if it was a video hosting platform, a single server would never be enough. You need at least two (as a fall back). Then you need dynamic scaling for bigger user numbers, which works just fine for CPU and RAM (or even GPU resources), but doesn’t work for storage. So you need extra storage somewhere all servers have access to, but when it comes to videos you’d be paying millions in no time.
So you need your own cheap storage and datacenters around the world. And CDNs on top to serve your content worldwide (otherwise the experience would suck on another continent if your server is too far away).
Look up how Google does it, they have their own data storage centers. And if your video is crappy and you’re a nobody, it probably gets stored in a slower location on-demand. So it also loads slower. But if your video is in high-demand with millions of views it gets pushed into a more accessible location (and gets higher priority for CDNs). It’s not just hosting, there is a massive amount of logic and software behind the stack.