Google has released a new Google Drive desktop sync client called Drive File Stream. It solves the problem of storing everything locally by only storing folders locally on your computer if you right-click the folder and choose "Make available offline". It also implements rudimentary file overwriting notifications. It is not as advanced as Dropbox's Microsoft Office "Badge" feature (which shows you who else has a Microsoft Office file open with a icon badge on the right of the document), but it does warn you if you attempt to save changes to a file that has already been saved since you opened it by someone else:
Neither Dropbox or Google Drive File Stream is as careful as a real Windows file-share, which will tell you *before* you open a Microsoft Office document that someone else has it open for editing (so you don't have to manually merge the changes you've made after the fact). However, Google Drive File Stream has a nice "history" feature where you can go back in time to any previous version of the file easily from the website. Google Drive is also much easier to make a cloud-server backup copy/archive of, as Dropbox does not have a centralized backup option.
Google Drive File Stream creates a G:\ drive on your computer, which shows you the same My Drive and "Shared with me/Team Drives" folders you see on the web version of Google Drive:
By default no actual files are stored locally on your computer, and any time you open a file it is streamed down from Google Drive in the cloud when you open it. If you want the File Stream application to cache the files locally onto your computer like Dropbox does for all folders by default (so that opening them in instant and they are available if you do not have an Internet connection), you can right-click on a folder and choose Drive File Stream > Available Offline, which will make that folder and any files/folders within it start downloading to your local computer:
The benefit of this new system is two-fold:
1. Less multi-master replication so files are only synced down to the computers and users that choose to keep an offline copy. This helps reduce issues with syncing files.
2. Google Drive File Stream files and folders appear to Windows to be native, local files (on the G:\), even when they aren't stored locally, so you can perform actions on those files without having to keep a local cached-copy of every file, saving storage space.