Its IDE is based on Scintilla. And it is very fast, even on an ancient PC it runs. It is specific for the programming language.
And here some advantages it has compared to a simple text editor:
Autocomplete of all functions and many API functions of the OS
Hints about parameters
F1 Help for all functions by just placing the cursor on them
Jumping to errors in the code
Automatic backups of all the progress of your codes, no problem to backtrace even if you forgot to save or commit.
Manage Projects (Groups of source codes and different targets)
Well integrated debugger
I agree with you in many points. Most other IDEs I am forced to work with are horribly slow. Especially those which rely on electron. Sometimes they lack features every basic editor has by now.