Maybe I'm missing something but I don't get "4. Slow, flaky tests". I understand that Selenium et al can be a pain, but how does server side generated code exc

Maybe I'm missing something but I don't get "4. Slow, flaky tests". I understand that Selenium et al can be a pain, but how does server side generated code excuse you from using it? Are you only validating the html structure and not testing any of the interactive capabilities?