I routinely do 1-4TB images of SSDs before making major changes to the disk. Run fstrim on all partitions and pipe dd output through zstd before writing to disk and they shrink to actually used size or a bit smaller. Largest ever backup was probably ~20T cloned from one array to another over 40/56GbE, the deltas after that were tiny by comparison.

I'm currently in the process of transferring about 50 TB from one zpool to another (locally), so I can destroy and recreate it.

I've downloaded a few torrents that were around 5 TB each, they're PS4 and Xbox 360 game collections.

As a single file? Likely 20GB iso.
As a collective job, 3TB of videos between hard drives for Jellyfin.

20TB (out of 21TB usable), a second 6x6TB zfs raidz2 server as my send target.

While I haven't personally had to move a data center I imagine that would be a pretty big transfer. Probably not dd though.

I think it would be my whole broken manjaro install, I just used dd to make a copy so I could work on it later lol. About 500 gigs