I accomplished this by using a File System sync that I put on my Google drive. I then bought an app for my Android phone that actually syncs the files to my phone (the normal Google app just allows you to work with them in the cloud). I sync the phone to the cloud based file system sync. It works well. It should work with Mac as well if the Google drive works the same way as Windows does.
I wrote about it here: If you want to sync Joplin via Google Drive . .