I have lost thumb drives. If I have the data on a cloud storage and synced to two desktops, I can lose any one of those and at worst I have lost a day's work. Remote stored with no local copies is putting you at the mercy of a service provider. Putting it on a flash drive is leaving yourself at the mercy of those assholes who steal people's bags on campus. Putting it in three places puts you in much less peril.
If one of those is a thumb drive, anyone who gets access to the drive can see what's on it. If you get my computer, phone, or tablet, you have more than a casual interest in stealing data to get into any of those.