Amazon is by far the largest e-commerce platform on the planet. It is well-known for the incredibly short (and cheap) deliveries and selling pretty much anything.
Looking for a new TV, but you would like to compare products, brands, read reviews, read more reviews and suddenly you spent at least an hour starring at the bright white screen. It is not a surprise that consumers in the US only spend 10 times more minutes on Amazon than while visiting the rest of the top 10 retailers, combined. (source marketingcharts.com
Not to mention that if you are on a such research quest, you are most likely doing it late at night after work. For an occasional shopping of some basic household products you might find it quicker doing it on your smartphone, but in most cases you would use your laptop.
Browsing and shopping from Amazon using a desktop or laptop is pretty much the norm for the majority of Amazon customers. 67% of all are doing so. (source Statistia.com
The bottom line is this - people are using their PCs to shop on Amazon and they spend a lot of time. One big issue is that Amazon does not offer a dark mode or any sort of darker UI that can help its visitors reduce the eyestrain they get from spending much time on it.