The loss from air itself is a tiny fraction of a decibel per kilometer.
But using an antenna means you lose 40-48dB in the first meter for 2.4-5GHz. And then you lose 6dB for each doubling of distance, so another 12-18dB for 4-8 meters.
If you're less than 20 meters from an antenna, not only do you have those massive upfront losses, you still lose more than .5dB for each additional meter of distance.
But using an antenna means you lose 40-48dB in the first meter for 2.4-5GHz. And then you lose 6dB for each doubling of distance, so another 12-18dB for 4-8 meters.
If you're less than 20 meters from an antenna, not only do you have those massive upfront losses, you still lose more than .5dB for each additional meter of distance.
Coax wins in almost every situation.