I would like to clarify that Google Backup and Sync is NOT a remote file system. It does allow one to specify a folder to be backed up to Google Drive, but these folders are not part of the normal Google Drive file hierarchy - they are stored in a separate space much like Team Drives are. The integration of the photos client is a nice touch, but isn't as useful for G-Suites or Apps for Ed customers since photos don't integrate correctly with Google Drive. (those users can vote for this function to be implemented at https://connect.googleforwork.com/ideas/4314 and https://connect.googleforwork.com/ideas/6405)
However, the unreleased enterprise sync program, called "Drive File Stream," works by essentially mapping a network drive directly to the Google Drive storage space - fully integrated into your OS (in Windows, it literally shows up as a network drive). The application is not public yet (I'm testing in their EAP), but for the vast majority of my Google Drive needs, this is a great solution and I'm in love with not clogging up my local storage with a bunch of files. I don't use about 90% of my files more than once a year and the extra time required to cache a file before opening is a nice alternative to requiring massive resyncs or file-comparisons every time I want to set up a new computer or workstation.
That said, I still use insync (along with freesync locally) to synchronize my array of devices and storage supporting my media server. Insync supports modular storage much better (though Google is supporting this now in a semi-cold backup oriented way), moderates overhead better (less lag while using the computer), has a nicer, faster interface, and most importantly, supports multiple accounts at the same time. Insync still has it's place, and does a pretty good job at it. They will need to do a better job with their modular storage support in the future though - Google is catching up.