i dunno if this has already been said, but to lift something as small as a frog, it takes a massive generator pumping out HUGE things of power.
therefore if we say the frog weighed 1 kg (hypothetically) we would need 50 times the amount of power to carry a small person (probs a teenager) then think about if we wanted to carry adults and really tall (therefore heavier) people, that would be like 90 times the amount of power.
i cant remember where i heard/read that. i think it was either in BtB or from my science teacher.
and i just crushed my own dream

science is annoying.