There are 2 things going for liquid hydrogen: the square-cube law and the rocket equation.
The square-cube law: the mass of the hydrogen in the tank goes up with the cube of the size, while the heat loss rate by the square of the size. Which means for bigger tanks, the refrigeration overhead goes down.
The rocket equation: the actual equation doesn't matter, but the idea is that you need fuel to carry the plane, then you need fuel to carry the fuel, than fuel to carry that one, etc. It all converges, but the lowest the density energy of the fuel, the more fuel you need.
Hydrogen has an energy density 3 times as high as kerosene, by mass. By volume, it's about 8 times lower. But mass matters more than volume.
A long range airplane, like the Dreamliner, starts with a lot of fuel at takeoff, about 45% of its total mass. If you replace that fuel with a fuel that's 3 times as energy dense, then you don't need only 3 times less fuel, but about 3.7 times less fuel. Which means the takeoff weight gets reduced by about a third. Which means you can reduce the structural weight of the airplane by a lot. Maybe not a third, but by maybe 20%.
The compounding benefits of having a fuel that's 3 times more energy dense are considerable. Will they be enough to overcome the need for cryogenic tanks and much larger volume of fuel? I don't know, I think it's a close call. But it doesn't sound absolutely crazy to me.