Also the guys doing the videos are re enactment pros and yes what they do is a bit theatrical, but other YouTubers specialising in this area have said it's quite legit. I'll link to video when I have a chance
Several people knock or drag the victim to the ground while the rest take turns beating him. In the movies when the hero goes to fight 20 dudes, at any given time 18 are standing around doing nothing while he lays waste to them two at a time with flawlessly executed martial arts moves. That's pure theatrics, and no amount of armor or training or general badassery can make it a reality.
Here we are talking about a fully trained knight in his peak condition with really good armor and sword. The bandits/peasants in the video are not very well protected and don't seem to take advantage of their numbers due to inexperience/fear factor. Also in the video he does fight 3 or 4 people at once and they do try and make him fall to the ground, but again he is trained and knows how to keep his distance and stay upright and he also takes damage.
You could argue that it might be not 100% realistic, but I think it does show the effectiveness of knights. I mean think about it, if a knight could be taken down by a bunch of peasants, why did invest so much time and money on knights and armour.
Here is the video review by Skallagrim
Taking advantage of their numbers doesn't require experience. Kindergarteners gang up on each other. It's instinct.
> if a knight could be taken down by a bunch of peasants, why did invest so much time and money on knights and armour.
For the same reason we invest in soldiers today. As a group, they can be a formidable force. But if a single one gets mobbed by 20 enemies up close, chances are he's going down no matter how elite or well trained he is.