I’m afraid there’s a slight misunderstanding in the second paragraph. In free space, all electromagnetic signals are capable of travelling the same distance. The wavelength is irrelevant. An obvious example is the signal received by your Sky dish. The wavelength of Sky TV signals is much smaller than that of Wi-Fi but you can pick it up all the way from space. Or — even more obvious— if short wavelength signals can’t travel far how does sunlight with a wavelength of only a few hundred nanometres ever reach the earth?
The three main reasons Wi-Fi signals don’t travel far are (a) the transmitters have very low power; (b) the signals are readily affected by the physical environment (absorption, refraction and reflection) and (c) they get drowned out by the background interference from all the other wireless transmissions in the same frequency band (other Wi-Fi, Bluetooth, microwave ovens etc.).
In contrast, FM radio transmitters operate at millions of times higher power levels and their longer wavelength means that objects on a human scale are less of an obstruction to them.