Like any tool, cloud storage and apps must be evaluated for safety and effectiveness.
For my Basecamp database, I see less risk and much more convenience in the cloud.
It's more secure than most USB sticks. It has to be accessed using a computer running a password protected app. I don't have any secrets in there, no financial information. Even if someone could be bothered to hack into my account, and they knew what to do with a .gdb file, there's nothing of real interest to anyone. At best, they could theorize that my home is somewhere between waypoints Start N and Start S, which are about two miles apart. They can find a more precise location with a 30 second Google search. Who cares what route I used to reach Utah in 2016? There is just no sensitive information there. And with no additional effort, I always have backups of my database as current as my last internet access.
Working on the desktop PC or laptop at home, each machine always has up to date information, without walking from the kitchen to the office to fetch the memory stick. I don't need to remember to take a stick out of my desktop and put it in the bag with the laptop. I won't leave it behind at hotel, it won't slide out of a pocket, or get broken. I don't need to dig it out of my bag and plug it in (or try to plug it in and then turn it over and try again). It's just always right there whenever/wherever I launch Basecamp.