It’s not a sync solution but Panic’s Transmit app can connect to 11 cloud services including OneDrive, Dropbox, Google, Backblaze B2, etc. It’s an easy way to drag & drop / move files between your Mac and multiple cloud providers.
Great. I’ve been using Transmit since version 3 and have purchased several copies for users over the years. But I’ve never heard/thought of using Automator. Thanks for teaching this old dog a new trick.