The site is not "promoting" the singleton pattern. In fact, there is a "Tradeoffs"[1] section that calls it an anti-pattern in JavaScript.

In spite of that, there are plenty of reasonable use cases for singletons in many languages, including JavaScript. For example, ES Modules are effectively singletons. If you import the same module in multiple places, it only gets evaluated once.

Let's not turn the singleton pattern into forbidden knowledge.

[1]: https://www.patterns.dev/vanilla/singleton-pattern/#tradeoff...