Videos on YouTube fall into 2 main categories - Entertainment and Education. The problem is that YouTube/Google algorithm treats/ranks all videos as Entertainment.
Entertainment is subjective, Education is objective!
Some people like the latest Star War movies, others prefer the prequels, while people like me like the original trilogy ... and that's perfectly fine. Some people like Justin Bieber while others the Rolling Stones. Different people like different sports, food, art, fashion, professions ... and that's perfectly normal because it is all SUBJECTIVE, a matter of personal preference.
The famous proverb BEAUTY IS IN THE EYE OF THE BEHOLDER could be applied to almost anything related to Entertainment. Russians have a similar saying: НА ВКУС И НА ЦВЕТ ТОВАРИЩА НЕТ.
It is very difficult to objectively quantify what constitutes a good movie or song, a beautiful painting or person, etc. It is all very subjective, based on culture, family and education.
However, EDUCATION is not subjective.
GOOD QUALITY EDUCATION IS NOT IN THE EYE OF THE BEHOLDER.
Education is objective!
Education does not depend on people's preferences with regard to teacher's gender, age, appearance, hair color, cleavage, etc.
How can students evaluate their teacher?
A student, by definition, is somebody who doesn't know.
A teacher, by definition, is somebody who knows.
How can a person who doesn't know evaluate a person who knows?
How objective is such evaluation?
How can I evaluate the validity of E=mc2, when I don't know anything about Special Relativity?
Give the formula a thumbs up just because I like the way Einstein sticks his tongue out?
Educational videos on YouTube should not be ranked based on people's likes.
Over 3,500,000,000 people are not connected to the Internet.
And the moment those people connect to the Internet they are bombarded with educational videos suggested by YouTube based on its broken algorithm. YouTube wants to keep its audience on its platform for as long as they can so that Google can harvest more personal information which it can later sell to advertisers.
I used to blame the YouTube audience for its undiscerning behaviour, but I was wrong. Even though I think that students should question their teacher and pay attention to who is giving them the advice, the main responsibility falls on those providing the information/advice.
Google/YouTube, Facebook, Amazon have responsibility to provide people with good quality education.