In May 2010, I wrote about WeTransfer because large photos, videos and documents often did not fit in an email attachment. You could upload a file and send the recipient a link. That solved a practical problem without a USB stick or shared folder.
The link is the transfer
WeTransfer remains active, but its limits and features have changed since 2010. My old statements that sending always works without an account, that files stay available for two weeks and that everything is private are not current guarantees. Check the current account terms and the expiry date of each transfer.
Tell the recipient what you are sending and when the link expires. This matters when they may only download it after a holiday or approval round. Keep your own reliable copy of anything you will need again; a temporary transfer is not an archive.
Consider access and sensitivity
A download link is easy to forward. Check that its settings suit the material. Confidential documents may belong in a secure environment with access controls instead of behind a general link. If you use a password, send it through another channel.
WeTransfer describes how to check download status and expiry in the transfer overview, but you must still confirm that the right person received the file. The advantage I saw in 2010 remains: large files are easy to send. The care lies in choosing the right link, expiry and access.