Google Classroom Sync- Purpose?

I have seen several articles on HOW to sync with Google Classroom, but none that I can find about WHY or what the advantages to this system are? Please elaborate.

If you’re already using Google Classroom, it’s one less roster to have to update. I am a HUGE fan of that because I am responsible for maintaining rosters on so many resources, the fewer things I have to manually update, the better. When using picture/word logins, you have to manually add/delete students every time the class list changes. Using the personal login option requires the kids to have the class code for their section on the initial login. When you sync to Google Classroom, once your Google Classroom class is set up, you just hit the ‘sync’ button and you’re good to go. No class codes, no manually entering information, etc. I do wish the sync would happen automatically, though. You do have to remember to click the “sync” button every time the roster changes, but that’s still faster than any of the other approaches available here. I think it also keeps their data from one year to the next, so they can continue the learning from where they left off instead of having to start from the beginning every year.