I had to comment on this, which I saw a few days ago.
Boeing 787 Dreamliner operators have been using 3-3-3 seating in economy. That's 9 across.
Japan Air Lines has bucked that convention. They've gone to 2-4-2 regular economy seating, so that's 8 across. They've widened the seats a little, which realistically means a lot.
https://simpleflying.com/japan-airlines-boeing-787-seat-configuration-guide/
I really like the Dreamliner, and its ambiance and ambient features are great, but it does look like a 1.5x wide 737 in the back of the plane.
JAL's move probably works out to a loss of 30 seats, unless they now have fewer business class rows. But customers will think about the seating and it might cause them to pick JAL, which might mean fuller flights.
That part of the world isn't my cup of tea. I want to understand what people are saying and respond. It would be great for European - and North American - carriers to go 2-4-2, so you would get the great Boeing plane and a more comfortable cabin. I'm more on board with the latest Airbus 330 Neo, which is still 2-4-2 and I've enjoyed flights on it.
Look at this obviously more comfortable layout and nicer seating that Japan Air Lines is offering.