Earlier quoted context omitted.
> Imagine running a store, and then I ask you how many customers you had yesterday and what they are looking at. Server logs can provide this information.
Only in very simple ways. Realistically, you want to know things like, how many users who looked at something made a purchase in the next 3 days? Is that going up or down after a recent change we made? Many necessary business analytics require tracking and aggregating the behavior of individual users. You can't do that with server logs.
Businesses existed before tracking individuals was practical. Wanting something does not make it necessary.
> Realistically, you want to know things like, how many users who looked at something made a purchase in the next 3 days? Is that going up or down after a recent change we made?
Metrics like this had little benefit sales did not in my experience. And tracking might be acceptable if it stopped there.