There was never a 'problem' with jQuery apart from that it's quite a heavy file, especially for mobile, and some people want to stop having to download it.
It's never been faced by the problems that backbone, angular, react, etc. where they rapidly die as soon as something else comes along, because it's a well built utility library, not a framework that had to include nasty hacks to work.
But, technically, there are no problems with it. If it were included by default in browsers, everyone would still be using it over vanilla javascript as even the new vanilla javascript has really poorly designed and wordy APIs.
It's never been faced by the problems that backbone, angular, react, etc. where they rapidly die as soon as something else comes along, because it's a well built utility library, not a framework that had to include nasty hacks to work.
But, technically, there are no problems with it. If it were included by default in browsers, everyone would still be using it over vanilla javascript as even the new vanilla javascript has really poorly designed and wordy APIs.