We all love jQuery. This site is even dedicated to building beautiful examples that use the library. But there are situations in which jQuery is not the smart choice.
If you are using it only for simple DOM manipulation or an AJAX request or two, why slow down your page load times and introduce an additional dependency?
The problem is more severe on mobile devices. You see, although we include jQuery via a CDN like Google’s, it is still not free – downloading it and parsing it still takes time. The very thing that made jQuery popular – perfect cross browser support, also makes it too bulky for use on mobile devices.
After all, why would you need your mobile website to support old IE versions if it is meant to be viewed only on iOS and Android?