there's gambling and sports betting and copyright violations (aka Netflix of everything for free) websites, not just CSAM thats a problem. And "visiting" makes it sound benign. Using a website you can do all sorts of stuff. Anywhere there's user created content, you can do all kinds of illegal things and break all sorts of laws. Send death threats, drug deals, money laundering.
IANAL but many sites that sell illegal drugs can get you in serious trouble. And I'm pretty sure the same goes for terrorism related searches and even searching for illegal downloads.