Do I really need the JR Pass?

Hi, I'd like to make sure since I've seen different opinions on buying the JR. I'll be staying 10 days but plan to buy the 7 day pass
Here's my itinerary

We'll be arriving at Narita Airport and staying in 3 places
From Narita to Osaka, (we'll go down 1 day to Hiroshima and Miyajima to the Itsukushima Shrine) , we'll stay in Osaka and then go up to Kyoto and finally Tokyo, departing from the Narita Airport. I'd like a little orientation or advice, I don't know what would be more convenient and less expensive. Thank you!