This isn't "Windows Hello style." This program extracts features from a 2d image instead of doing depth reconstruction first. This makes it easy to fool with a piece of paper. Also this only handles user authentication unlike on Windows where it can be usedpasskey. disk encryption and for passkeys. Edit: This program also saves the landmarks of your face into a file in plain text when it gets added.
That said, without the depth reconstruction, I do agree that this is nowhere close to Windows Hello's features. That's not the devs' fault (that kind of mostly-secure facial recognition is very hard) but I also don't think the comparison is apt. But who knows, if this project gains popularity, maybe in the future that kind of thing becomes possible.
This is more akin to Android's facial recognition, except for using the IR camera. Which is still acceptable for plenty of people. After all, many fingerprint readers on Linux share similar risks and are often regarded as secure enough. I think the availability of this project, even if it's nowhere near Windows Hello's standards, is a great addition to many Linux desktops, as long as their users understand the limitations.
As for the plaintext, Linux doesn't really have a secure storage mechanism (even the standard secrets API is easy to fool) so obfuscating the facial features doesn't really serve a purpose. As long as your disk is encrypted, I don't think that's a risk (and if it isn't, whoever is looking at your laptop can just browse through your photo albums anyway).