It's mainly to work around bugs in the system. For example:

site: https://www.shawwn.com/thanks

markdown: https://www.shawwn.com/thanks.page

If you "view source" on the markdown page, you'll see:

  Twitter: <a href="https://twitter.com/theshawwn">@theshawwn</a>  

The reason is that [@theshawwn](https://twitter.com/theshawwn) didn't convert into HTML for some reason. I assume the @ character threw it off, and I didn't want to drop what I was doing to figure out why. But there are a million small things like that.

For https://collectednotes.com/shawwn/sample-note, I would put GA into my notes.