Why does iCloud Drive take forever to download a file?

I am a photographer. I keep MASSIVE amounts of files on my desktop and use iCloud Drive to sync them to my other devices. I have a very fast internet connection. When I go to move a folder that is over 100gb, it takes HOURS to download from iCloud Drive. Why? It almost feels like Apple wants it to be this way to ensure we don't try to use external storage to keep our files and continually have to upgrade our iCloud Storage plan. Seriously, this is the biggest tech corporation in the world, there is no way they throttle THIS much without an angle.