It has many disadvantages in terms of functionality. Some advantages could be: theming (line-height, inner margins, inner max-width), runs in the browser, easy to modify and build upon, produces HTML output.

I haven't tried the subject of this thread, but since I upgraded to Windows 10, the notes application has become ridiculously slow. Sometimes I have to wait, and wait, for it to respond to clicking or typing. I assume because it's doing some sort of network/AI enabled nonsense.

While the page doesn't use js, it is there for you to use.

document.body.innerText += 'hello world/n';