The recent price rise from ¥10,000 to ¥15,000 is a kick to the wallet, but I can still see how it brings opportunities to visitors who want to experience the bullet train and are willing to give over 3 consequential days to sightseeing.
A day trip to Karuizawa alone would be ¥12,000.

I would definitely advocate for anyone wanting to scratch their shinkansen itch by taking on a day trip to Karuizawa, a day trip to Nikko, a winter/early Spring day trip to Gala Yuzawa or to Mito to see Kairakuen, using their JR Tokyo Wide Pass on the JR EAST bullet trains. Even if you only use the Tokyo Wide pass for two day visits, it can still cut the price of onward travel (past Saku-Daira to Nagano, past Komoro to Matsumoto, or past Nasushiobara towards the North). There’s always bus travel for the return trip.

It’s not for everyone, but it still makes a terrific consolation prize for new visitors to Tokyo mourning the previous JR Pass.