What particularly interesting about such tests, there too are common misconception in place.
In movies (and other entertainment) often enough armor aren't shown to be all that effective. Which rise the question why people wearing one in the first place. (interestingly, in actual medieval literature and art battle depicted exactly like this, with plate armor slised to bits left and right
![Stick Out Tongue :p :p](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
)
As a reaction to this some people (who undoubtedly believe themself to be above the "amateurs"
) started to claim that the opposed was true, that medieval armor was completely indestructible. Supposedly nobody would use one otherwise.
As this and similar tests shows, armor can be penetrated. Of course, as they say themself in the video, stabbing steel plate on a stand is not same as stabbing steel plate mounted on big angry dude who want to penetrate you too. +it's much easier to stab between plates, or where plates isn't (eyeholes, armpits) than penetrating plate itself.
There important to note that actual survived medieval armor varies wildly in quality. Some cheaper pieces are quite shitty. Not everybody could afford top products. What also should be pointed out, that often that was enough. As example, we have chainmail coifs (hoods), known from both archaeology and medieval art. Good direct strike with the sword would just crack skull of the wielder. However, landing such direct strike at moving target, who actively fight back and has shield, wouldn't be easy...