Sure, but it's basically a very thin wrapper on the built-in RichEdit control, with some added menus and niceties.
Don't get me wrong, it's hundreds of times better than whatever UWP abomination they call Notepad in Windows 11 nowadays (with logins and AI features), but it's not an actual text viewer / editor from scratch.
I think the original notepad.exe was just a Win32 Edit control (whatever it was called) with a window and some menus. I expect that Apple's TextEdit.app is just a wrapper around the rich text control in Cocoa, too.
But yes, it's hardly writing a text editor to write a Win32 app in assembly. (Although, if they used the COM control and did that in hand-written assembly, that would at least be an impressively tedious mortification of the flesh.)
> thin wrapper on the built-in RichEdit control
> UWP abomination they call Notepad
Kind of weird for both of those things to be true. I thought the latter was mostly the former. But I’ve been away from Windows for a loooooong time it seems.