JR 7Day pass worth it?

Hi there,

Following the calculator it would be cheaper for me to get single tickets than a 7day pass.

Itinerary:
21 Sept: Hiroshima - Miyajima - Hiroshima
22 Sept: Hiroshima - Osaka
23 Sept: Osaka
24 Sept: Osaka - Kyoto
25 - 26 Sept: Kyoto
27 Sept: Kyoto - Tokyo
28 Sept - 1 Oct: Tokyo

Calculator (Single Tickets): aprox 26.000 JPY (including ferry to Miyajima)
7day pass: 29.000 JPY

I would use the JR 7day pass during 21-27 Sept (or single tickets) and then in Tokyo I would use subway or 72hr card (for I can see JR pass is not the best option to travel within Tokyo)

Why to pay 3000 JPY more for the 7day pass? Is there any other benefit than just the convenience of having one ticket (and not to have to book a few)?

Thanks!