fzf presents itself as a general fuzzy finder tool.
QFC is a specific tool for completing just file/dir path.
If you use the two, you will notice the difference quickly.
Sorting && Filtering isn't the same, for example:
If you write 'bin' and there is a matched directory for that string ('bin'), you will see only the dir path not all files inside the dir.
Also, you can arrow keys to navigate between directories.
You can also type special characters like '~', '$HOME' etc..