Actually..
At a printing outfit we run a secure FTP service using FTPS (FTP over TLS) which is supported by all decent modern FTP clients such as Filezilla. It's used for clients who need to send very large files to us.
We do have a pretty advanced browser based uploader but it doesn't work well when e.g. clients are behind a slow or unreliable network connection. Also sometimes a combination of browser, add-ons and/or the phase of the moon just randomly stops things working.
A secured FTP service is useful over something like SCP because a) non tech savvy people have generally at least heard of FTP and any other acronym scares them off and b) it allows for very secure jailing of the FTP user from the system at large.
Sometimes it's easy to forget that not everybody has super fast and reliable internet, and FTP over TLS is nice for those users because you can choose to secure just the communications between client and server but perform the transfer unencrypted. The data we are receiving is not exactly top secret blueprints so that can be a lot faster and more reliable for these users.