While I am a Prime member, there are still some things that I cannot find or be had on Amazon, and more than often those one off things are not covered under Prime. I am in the process of finding motorcycle helmets and very few that are prospective for my cart are not under Prime.
It also depends on what marketplace sellers offer Prime too, not everyone does.
The media access in music and videos are just a bonus - because even then, not many free options are available outright in access. While the lending library of having access to one free book a month is nice, it is but one book (and only through a Kindle device AND Prime) - and the book doesn't stay in your library. There is the Amazon's Firsts, where you get a free book out of four options for a first release opportunity (this perk is not device mandated).
In short, if one buys often a year from Amazon, the two day shipping is the biggest reason to have Prime. If one doesn't check out of Amazon over 10 times a year, then Prime may not be worth it.
Amazon, while consolidating sellers and storefronts under an easy system, shouldn't be put on a divine pedestal.