3000KiB/s or 24000kbps, that's 3.5-5x my UK broadband bandwidth [depends on the weather!].
UltraHD video is about 7GB per hour, or about 2MB/s.
Mind you I'm surprised that Ofcom actually reports average UK bandwidth to be 4.5MB/s (SamKnows study; self-selected group of 2000 participants AFAIK).
Like 3MB/s maybe? Even that is pretty optimistic however. The older Pi wouldn't even do a MB/s