It's funny that in the first example where the author asked the viewers to find the function definition, I was able to do so faster with the colorful syntax highlighting he considered wrong.
To recognize different elements of code is more than just colors, but actual syntaxes of the language and the general shapes of code blocks.
It's a matter of taste, and in my decades of programming, I've found colleagues and many teams trying for all kinds of fancy themes only to come back with a "boring" one, like Material Theme, which is also my main driver nowadays.
I think the author had some good ideas, particularly around literals (what he called constants), rejection of the requirement for equal brightness, and emphasizing comments. The author is more than welcome to bring his version of perfect syntax highlighting to the market of ideas. Its adoption should prove it if his idea wins.