I think I disagree with the video.
I have a mother who is ISFJ and she has no problems with social events like church and other gatherings.
The thing she does not like to do is debate issues she has no opinions about. Whereas INFJ have more abstract ideas.
So the thing about The Fe function makes no sense from the video. Fe handles social stuff much better than Fi does.
With Fi you get two kind of people. That obstinate kind and the rejected kind.
The way Fi deals with social stuff is that they don't. They either like you or dislike you and that is that and having to be in public this means they do not observe people because they either get really angry or sad, this being "upset all the time" because of other people or they shut down completely which is mostly opposite to Fe - Fe rather can take in all sorts of things from people and NOT react to it. Thinkers who have Fi react by trying to debate you. The S types with Fi just act out against themselves or other people. They way S types deal with croads is to avoid them or be center of attention.
Since right now I am INFP I just avoid people who upset me the best I can if they cannot be reasoned with. I do not have as strong a compulsion to be right as T types but I do have in me an aversion to being told I am wrong because it creates an insecurity derived from Fi
When people tell me stuff I think is not true how I see it I mostly rely on Ne to show how things could be different but that does not always work. People eventually try and corner you into things that have nothing to do with what you believe. It keeps me away.
I do think that INFJ can have energy drains but it is even more a problem for Fi types who cannot, "not" react in some way.
ENFJ and ESFJ I think are the least reactive types when it comes to people. Because of the Fe function being first.
With all that said the way Ni is as to zen like qualities. I do not think that reduces energy as much as it blocks it out.
In fact blocking out energy requires energy so the video has a misunderstanding of introversion and extraversion.
Extravets absorb the surroundings. So if you have Ni first and Se last that really is not about how all extraverts getting energy.
It is more about what makes the energy. The inside world makes the energy or the outside world makes the energy.
So Fi makes too much internal energy that Ne and Te absorbs.
But Ni creates too much energy that SeFe has created, that is for any introvert. (The Ti and Si as well)
In the Extravert the Introverted functions are weaker, make less internal energy so the Extraverted function can balance absorbing it from outside.
Ni then, blocks out what it has already created. Even with Fe
But Fe is less people reactive than Fi which created to much for the Fi type to deal with people in the first place.
Fi types can become non reactive but it takes a real effort in directing the internal energies involved.