I don't find this convincing as an introvert. Dealing with shyness or being an introvert required me reading a few books and techniques how to deal with it. In the end that helped, but it was not as easy as just 'try harder' and took a few years.
I also wish I realised earlier that it was an issue that needed addressing, but no one told me that.
Overall the article seems to trivialize the issue in my opinion.