[bryanrasmussen]

Since JavaScript evolved to incorporate many of the APIs that jQuery pioneered at some point knowing only jQuery was not such a problem.

But even before this evolution much of jQuery was just sugar to make cross-browser problems manageable.

I am not actually aware, I think, of any developer that just knows React but if they exist I suspect they would have an even harder time of it when deprived of their favored framework than those developers back in the day that just knew jQuery.

[austincheney]

Query selectors likely came from jQuery's Sizzle engine, but most of the jQuery APIs, all methods, were never adopted. The best I can think of that did get adopted is closest which uses a query selector to find a matching ancestor node.

The reason why most of the jQuery approach is not adopted is because it is so incredibly slow. First you have to consider that query selectors, at their best performance (Google Chrome), are about 460x slow than the old DOM methods. All the jQuery approaches would be slowness that multiplies on top of the already slow query selectors. In Firefox query selectors are about 10,000x to 250,000x slower than the standard DOM methods.

From a standards perspective there is no incentive to go down that path as it cripples the interface it describes.

[bryanrasmussen]

I was pretty much thinking just of query selectors as I think that would be the most problematic thing for a jQuery trained developer to do without.