I suppose they could, but even cold storage has a cost, and with the scale Discord’s operating at, they definitely have many terabytes of data that comes into the CDN every day, and that cost adds up if you’re storing it permanently.

I also think the vast majority of users would prefer being able to upload much higher resolution images and videos, to being able to see the image they sent with their messages a year ago. I don’t often go back through my messages, but I often find myself compressing or lowering the quality of the things I’m uploading on a regular basis.

They could also do the other common sense thing, which is to, on the client side of things, compress images and videos before sending them.