The article's POM depends on spring-boot-starter-web. Here are some of the things you get with that:
* Dependency Injection (@Autowire)
* Externalized configuration (change app settings via CLI or environment variables) with profiles (think DEV,PROD)
* Out of the box logging (think log levels, configurable per logger)
* Remote administration via JMX (runtime administration)
* An ORM (Hibernate)
* A unit testing framework with mocking (JUnit, Hamcrest, Mockito)
* Remote debugging via JVM debugging port
Going beyond the simple app, you can take full advantage of the Spring Boot ecosystem of dependencies to pick and choose only the dependencies you need, while being able to do anything that a cloud app might need to do.
If you don't need all that, you can always fall back to the simple HttpServer example he gives in the article and still get a small footprint.
The article compares Java 8 to the others. I'd love to see a comparison to Java 9, where hopefully the modularization of the JVM will lead to a smaller overall runtime and memory footprint.