Did you have a counter argument for calling bullshit? Because he probably had a point, there is definitely a niche for that level of security. It just generally involves state secrets.
Certain classifications of documents require access only from physically secure locations, called SCIFs, where all access is monitored and logged. Things like phones and cameras aren’t allowed to prevent any data leakage.
That’s not too say you can’t be secure remotely, but really only against outsiders. Good luck stopping an employee from taking a picture with their personal phone of classified blueprints off their monitor at home. Good luck even knowing they did it before the data is gone.
When you factor in social engineering being the most successful type of “hacking”, an office setting is undeniably more secure. However, most offices don’t need that level of security, because data breaches aren’t a matter of national security, so remote is an acceptable risk.
RAID is redundancy. It saves your data if a or two drive fail, but does not help you if the entire RAID system dies (power surge, fire, water damage). Generally if it is on the same system it is not a backup.