There is also write.exe or, just a suggestion, buy MS Office Word in a package deal for like ninety nine bucks. I can see why notepad might be deemed unimportant by Microsoft with both a commercial alternative to push and a more powerful editor also built in. (Assuming write.exe is still in W11, last I used was 7 I think.)

Those applications are absolutely not suitable for text editing because they have a tendency to mangle the text encoding and other CR/LF characters.

(I generally don't think it's too odd for an OS to ship with a text editor of some kind. I don't use notepad much but there are a few times that it's been a life saver.)

So Notepad is not core OS functionality because you can buy Word for only $99 to edit your config files? Am I getting this right?

You edit config files in Windows? Registry is all the rage there, unless you use tools made to be cross-platform (which, for devs, is obviously a lot, but I can see an argument that notepad isn't that important to the OS).