Perhaps I missed it but they should have linked to BrowserLeaks [1] and IPLeak [2] as most people will not be running tcpdump/wireshark on their router unless they have a root shell on their consumer router. In my opinion those should be at the top of the article and open in a new tab. Perhaps also WhatsMyIP [3].

[1] - https://browserleaks.com/

[2] - https://ipleak.net/

[3] - https://www.whatsmyip.org/more-info-about-you/

First, it's definitely an ad post and I won't click on it.

Second, there are probably thousands of people who, if they need to, can see what you personally do on the internet at any point in time.