jQuery is a library of shortcuts. Everything you can do using jQuery you can do without jQuery, but that's like saying everything you can do in Excel you can do with just a Calculator app. Yes, it is possible, but why would you want to?

When you do things like drag & drop and interactive resize you have to query DOM to get position and sizes, and perform hit detection, and you have to manipulate DOM directly. jQuery is very convenient for these kinds of things.