For reference https://vaclavsmil.com/wp-content/uploads/2019/03/January2019.pdf says
Jet airliners are surprisingly efficient, commonly requiring around 2 MJ/pkm (=3.22 MJ/pmile). With full flights and the latest airplane designs, they can do it at less than 1.5 MJ/pkm (=2.41 MJ/pmile)
So 6x is still a big difference. Not sure what I expected, but maybe this is smaller.
It still loses to HgBa2Ca2Cu3O8+6 with Tc = 133–138 K at normal air pressure, though. (I assume it's normal air presure as the article doesn't say the pressure for it, while it refers to some others as high-pressure ones.)
Maybe LK-99 still has other benefits, such as not using mercury.