Short answer
WeTransfer is best known for simple large-file sending. ZipPigeon is positioned for sensitive handoffs where encryption before upload, encrypted storage, recipient access, expiration, and metadata transparency matter more than a broad consumer transfer flow.
When WeTransfer may fit
A simple transfer service can be a good fit for low-risk files, public creative assets, or workflows where the sender mainly needs convenience and the recipient experience is the priority.
When ZipPigeon may fit
ZipPigeon is a better fit when the sender is delivering confidential documents to clients, vendors, employees, counsel, accountants, or partners and wants a narrower security story than ordinary links or email attachments.