Why? This still allows the ad tracking and other malicious Javascript, and it still requires you to recognize that there are ads on the page. The cost in mental effort is significant; if you think it isn't, live completely ad free for a month or two to reset your tolerance.
It depends on the tracking. They are far more advanced than simple cookies these days. Some do use javascript to load things and/or report back without resorting to easily-deletable cookies. Whether something qualifies as malicious or not is a matter of opinion. Imho any tracking attempt by unnamed third parties (ie without my say so) is evil.
For example, Chrome keeps Google analytics connections open for 4 minutes since the last request, even cross sites. This is a cookie less, IP less of uniquely identifying a user.
