What is tricky about jQuery's nth- filters (:nth-child, :nth-of-type, etc.) relative to other filters?
Referring to lists of items, they are 1-indexed (like CSS), not 0-indexed (like JavaScript).
They are not part of CSS, so they don't get the performance benefits of passing through the document.querySelectorAll.
document.querySelectorAll
They don't return the jQuery object, and cannot be chained.
They can return the wrong items if the DOM was recently manipulated.