Re: "FTP is an insecure protocol and there are no reasons to prefer it over HTTPS"
And on top of this, many FTP implementations include a chroot jail actually in the server.
And even it it isn't, it's been very common practice (for about 30 years or so) to set up a chrooted environment for ftp explicitly.
The exceptionally low overheads of ftp have often kept it a as an option in bandwidth constrained environments. But it's time will end eventually.