Web components are implemented using custom elements which are just plain JS classes that extend the HTMLElement class, so you would access the property the same way you would access a property in a normal JS class.

The author of the thread is arguing against properties.

Yes, I know. I wasn't making a prescriptive comment about whether or not developers should use properties, I was just making a descriptive comment about how properties are accessed in a web component to answer the specific question politelemon asked.

Thanks understood, that makes it quite simple and intuitive thinking about it.