I had 10 days there recently. Note I based in Tokyo and took day trips to places within 3 hours by train or bus.
I loaded my Suica card electronically to the iPhone wallet and topped it up with a direct link to my Visa.
I used an eSim to access data & Whatsapp while there that worked fine (I didn't need SMS or Phone)
The local 7/11, Family marts, Watsons, department stores etc are all credit card.
All the restaurants, coffee shops, sushi shops I used accepted CC except a couple small <10 seater type places.
I had a couple massages - CC.
In the airport outlets, cafes etc all CC
Some small shops street vendors might want cash if you buying a snack or drink while wandering around.
In the end I was using the cash that I exchanged before I travelled in places that would take CC or cash just to use it up.