The biggest mistake I see with fast beauty effects is using the fact that a tool can remove texture as evidence that it should.
It shouldn't.
Skin has pores, tonal variation and small surface details. Once too much of that information disappears, the face can begin to look disconnected from the rest of the image.
In the footage shown in my tutorial I reduce the smoothing to around 20 because that gives me a noticeably cleaner result while retaining far more believable surface information.
Important
Treat the value shown in the tutorial as a starting point, not a preset. Different faces, lighting conditions, lenses, resolutions and levels of compression can all change how much treatment is appropriate.
Look at texture before looking at perfection
For beauty work, I want polished skin. I don't necessarily want perfect skin. Those are very different visual goals.
A believable finish normally comes from reducing the distraction while leaving enough natural variation that the subject still feels physically present in the scene.