I hate when a program assumes and inserts characters I didn't ask for. Please create an option to turn off auto insert curly braces or anything else. I don't know why someone would think this would be helpful. I'm finding extra curly braces everywhere because of this stupid thing I didn't ask for.
Welcome to the forum.
It is indeed terribly stupid. When I want to type my thoughts, it is as if an invisible hand is trying to mess up everything that I type. I costs me a lot of extra time to constantly verify what I am typing and fixing what that invisible hand disrupts.
Here is a simular question: Editor Preferences in 2.0
Press F1 in the editor, type "preferences" to search for it. Then click on "Preferences: OpenSettings (UI)" (which might be hardly visible if you used it before because of the text colors), and there you can turn that off.
It took me a long time to find it 
In those settings, go to "Text Editor", then find "Editor: Auto Closing Brackets" and set it to "never".
Or type in there in the search bar "closing b".
I have also set this to "never" : "Editor: Auto Closing Quotes"
I noticed that the "Editor: Default Formatter" is empty.
You will be bankrupt if you have to pay everybody that forgets a closing '}' one cent 
Considering that Arduino is basically for beginners, I can imagine that automatically adding a closing '}' is useful.
Suppose a painter has a creative mood is going to paint a once-in-a-lifetime masterpiece, but a witch doctor has put a spell on the painter so everything that is painted will automatically get the same thing in complementary colors right next to it. That breaks the concentration of the painter, and the painting is full of smudges because of all the things in complementary colors that had to be removed. No one buys the painting, not even for one cent. The painter has no money for rent or food and will be bankrupt.
All because a witch doctor turned on the "Auto Closing" option.