The author of the text, Phil Nash, discusses how Twilio's Add-ons marketplace can simplify development by providing pre-built services that handle tasks typically requiring custom code. In this specific example, he replaces a sentiment analysis service using AlchemyAPI with an IBM Watson Message Sentiment Add-on, resulting in reduced code and maintenance requirements. The author highlights the benefits of using Add-ons, including saving time, effort, and code, and showcases additional available Add-ons that can enhance application capabilities.