McDonnell-Douglas did a feasibility study in the early 80s using a DC-10.
Every thing Rickair said. Plus: Cryogenic fuels have to be in strong spherical tanks.
You can’t put them in the wings and get any workable capacity. So, their study had two big tanks in the fuselage.
Result: could carry about 80 people SFO to DEN.
Impractical. A flying wing might work, but others have discussed before how uncomfortable or dangerous a ride in a big wing could be for passengers far from the roll-axis of the plane.