I think your friend may be referring to the effort required playing both instruments. I notice a difference in the pressure applied to the fretboard and picking hand, including muting techniques, when I play acoustic.
I barely need to apply pressure with my LP for most things and even when doing bends, vibrato, etc........... requires a lot less exertion in comparison.
Then there is the effects portion. Delay, chorus, reverb, etc....... Help to emphasize by fattening things up and getting some intense sustain when desired.
This by no way means to state that playing electric is easier. Mastering an electric guitar takes a lot of talent and painstaking discipline in order to play it with clarity.
To me, they are two different instruments and the talent necessary differs in the order by how they are desired.
I know a couple of great acoustic players who can't play an electric even close to the talent they possess.
I have the opposite situation. Although my results playing an acoustic are satisfying, it is nowhere near what they can express.
I believe that this is apparent with a lot of players, depending on which instrument you're most passionate with.