Is writing a markdown text editor the new "hello world"?

Check out these:

http://www.koi-writer.com/editor/

http://darkcopy.com/

http://gun.io/w/yyhegyfn6

https://quabel.com/

http://www.wabisabi.cc/

https://writeapp.me/

http://pen.io/

https://draftin.com/