I have seen alot of site with adsense but very few integrated with affiliate does affiliate make more money or adsense publisher make
Accoding to my observation, I have seen that adsense is not generating as much profit as they were generating before. This does not mean adsense is useless. Adsense is still working very well for a lot of webmasters because they have reached in a level from where they can easily dominate adsense earning. Affiliate marketing has started creating it's appeal and the number of website integrating affiliate are increasing everyday.
If you optimize you site for adsense it will make you more money than if you selling products. If you want to sell only products it is better to not distract visitors with ads.
but why does more popular highly traffic site just rely on ad sense income than affiliate marketing strategy
It depends on what kind of site you're running, high traffic websites can make a killing off Adsense, but not necessarily affiliate products due to the type of traffic. The visitor may be there to see a video, or read an article - they don't care about any product for sale. So to answer your question; there's not one that makes more than the other, it's all relative to what you're doing.