Love WinSCP hate FileZilla but ...

FileZilla is (approx) a million times faster to transfer files (PC - Internet Server). I have thousands of files to up and download, so I am forced to use FileZilla. Does anyone know why WinSCP is so (comparatively) slow?

Do you use transfer queue in WinSCP to use parallel transfers to speed up transfer of lots of small files?
https://winscp.net/eng/docs/transfer_queue