There are plenty of gotchas when serving a static site via CloudFront. Let's say you have a page at example.com/foo/index.html. If you want it serve it from example.com/foo/ then you need to write a Lambda@Edge request function to handle the directory index — the article implies that CloudFront's default root objects handle this, but they don't. That's for the domain root only.
There's also the case of redirecting example.com/foo to example.com/foo/ (adding the trailing slash). That requires a Lambda@Edge response function. It's all a lot of fun to get working, but you do start to wonder if your static site really is static.