I use both git and Dropbox, because I have multiple devices to sync: laptops, a desktop, and linux servers.
If you use a desktop and a laptop back and forth, git is quite inconvenient. You don't need to commit and push from the desktop to switch to the laptop with a folder level realtime sync solution.
Also, git only protects files that are staged, but Dropbox can restore any files to any point of file event (not periodic snapshot, but it keeps all file events). So combining both you are safe from any kinds of mistakes.
I use Dropbox because Google Drive sync wasn't stable enough for this kind of workflow but I am not sure if it has been improved lately.