Even the 340-500 has a higher Max T/O weight than a 777
maybe, but a very much lower payload (if i'm not mistaken around 48t, to vrfy).
Anyway, both AB have a lower MTOW to max payload ratio.
And for the 340 it may be explained through age, but not with the so called most modern, most fuel efficient airliner.
It's simply not true unless your calculator is a AB product ....
Nothing against the big bertha, but the numbers are not impressive.