I once considered that the air surrounding a model aircraft was effectively more dense than the air around a full size aircraft, I did say "effectively" not actually.
The analogy of the model ship looking as though it is sailing in thick oil rather than throwing up fine spray.
The big aircraft must fly faster to maintain lift.
The wing loading (area--weight) doesn't consider relative (effective) air density, the density is considered constant.
Maybe I'm all wrong, the instructor I mentioned it to told me to bugger off!