Why we use IDE for c# programming?

Answer 1

It is much easier to work in IDE, it highlights syntax and do a lot of thing to help you and prevent some mistakes with namings(Like you declared variable, but misspeled it's name later)

Also they automatically links all libraries and packing your code. So you dont need to write a lot of hard instructions to run compiler by hands.

So they are developed for faster programming and auto-little-mistakes-correction :~)

Answer 2

IDE also offers an easy way to make custom GUIs. It would be pain in the a** to code whole gui.