When it's your job job dealing with huge data it quickly becomes very time consuming and error prone to deal with multiple external storage devices. (edit: by error prone I mean human error eg where did I put this stuff?)

8k raw video is very large - even a single project will fill that up and need extra storage to add externally.

A couple 4k cameras filming at 60fps at, for example, tech conference and you can about fit a single days footage on those 24TB,

If you're on location filming a nature show, yes. It's less to upload.