This is written by someone who has never used jquery or forgot it. The beauty of jquery was not being able to use CSS selectors to find elements, but in being able to work with multiple selected elements as if it was a single one.

Ok, you will say, but you can always do

[... document.querySelectorAll('.foo .bar')].map(it => it.style.backgroundColor = 'corn');

instead of $('.foo .bar').css('backgroundColor', 'corn');

and it is clearly better because it does not use jQuery.

Don't get me wrong, jQuery has many issues that make it a very poor choice for big modern web applications, but please don't tell me that it can be replaced by querySelectorAll.