But people don’t use it on new projects because there are more better library & you can do the same thing using vanila js. Check this out – http://youmightnotneedjquery.com/
jQuery has lots of plugins which can help you to do things easier
Bootstrap still using the jQuery
jQuery is really lightweight and it’s also hosted in google so you can use cdn in your project very easily
It will be better if you start with other js library/frameworks instead of jQuery(use react,angular & vue logo image here)
Do you want to use jQuery in your new project ?