First of all: Good for you, welcome to a better world :)
Secondly: Looking at the JS you wrote there, it looks very tedious. I agree that VanillaJS is very important. But at the same time, it is just as important to keep proven ways to make your life easier. You should write a wrapper for that construct or use a library which contains that wrapper for you. Preferably one which is lightweight and just wraps over VanillaJS instead of introducing its own objects and methods for every little thing.
As for what I replaced: Nothing, really. If I already use jQuery in a project, I will keep on using it. I am not paid for removing jQuery, just for the heck of it. I will, instead, relinquish it in future projects. But if I had to pick one thing which I wrapped, it would probably be $.ajax(), since I use it quite often :)