Thanks for putting your thoughts out there. It is important to think about performance and the quantity of HTTP requests your application requires.

HOWEVER, you shouldn't publish an article where your main argument is not backed up by proper research and data. As many have pointed out, CORS preflight headers can be cached. For most back end technologies, they're also cached on the server side as well, so the request is extremely light and performant on your back end service.

Understanding CORS is the key to building quality front end applications. What it is, why it exist, and what you should use it for.

As developers publishing about technology we are responsible for doing thorough research instead of publishing half baked opinions about 'what not to do.' These types of arguments are pervasive and damaging to web development as a whole.