What are some alternatives?
When comparing Syncthing and Box, you can also consider the following products
Dropbox - Online Sync and File Sharing
Mega - Secure File Storage and collaboration
Google Drive - Access and sync your files anywhere
Nextcloud - With Nextcloud enterprises host their own secure cloud solution for storage, collaboration & communication from any device, anywhere.
Microsoft OneDrive - Secure access, sharing & file storage
ownCloud - ownCloud is an open source project enabling businesses to host their own cloud storage while maintaining regulatory and compliance needs.