Electrical engineer here. Just to bring some insight to your part about "Can this be used to send internet to households instead of fibre"...
Optic fibre is, and will likely remain the fastest practical medium for internet speeds. The reasons for this are:
1) visible light has the highest frequencies that don't give out ionizing radiation. Ionizing radiation gives us cancer, and is radiated by things such as ultraviolet light (skin cancer from too much sunlight), x-rays (you will get cancer if you have excessive exposure to x-rays), and gamma rays (nuclear bombs etc). Anything of lower frequencies only gives heat radiation, and can cook us if it's too high energy, but otherwise is harmless.
2) The raw maximum data transfer without applying any multiplexing (eg
https://en.wikipedia.org/wiki/Frequency-division_multiplexing) is simply half of the frequency of the signal. Thus for visible light, this is around 750 THz for violet light, and thus raw data transfer of up to 375 Tbps. For the fastest version of 5G (which isn't being implemented yet, all the 5G we are starting to get now is much lower frequency), this is around 40 GHz, and thus 20 Gbps. Note that all kinds of multiplexing techniques can be, and are, applied, and thus the theoretical bandwidth achieved can be much higher. However, various versions of these techniques are used by all of optic fibre, 5G, USB, TB3, ethernet, everything, so it's useful as the starting point of these comparisons to start with the raw maximum limit. And thus, a single strand of optic fibre has around 10,000 times the speed capability of 5G. And that's just a single strand. Use two strands and you've just doubled your bandwidth without any multiplexing. You can't double the air, so 5G has only one "strand". Use a 864 strand optic fibre cable (which is commonly manufactured), and you've got roughly 8,640,000 times the raw bandwidth of 5G, and so on. The one advantage that 5G (And 4G, 3G etc) has, is simply mobility. Also note that part of the reason why the faster and higher frequency versions of 5G aren't being implemented, is that the higher you go with these frequencies, the more the signal is blocked by objects, and the more you need direct line of sight. Thus, anything faster, such as a 6G will have very limited, direct line of sight usage. We will, however, keep on refining the multiplexing techniques, as the hardware gains more sophisticated abilities to split the signals into finer bins.
3) When comparing other cabled methods (e.g. ethernet, USB, TB3) , all those methods transfer electricity through wires. These also have the same formula of half the frequency for maximum raw bandwidth. However, as you increase the frequency of an electric signal in a wire, you get all kinds of problems with the electric energy being converted to magnetic energy, and leaking out of the cable. This is helped with things like twisted pairs, and shielding, but it get expensive, and doesn't solve the problem, it only helps it. The energy attenuation is also mitigated by reducing the cable length, thus why you see short maximum cable lengths for some higher speed data transfer protocols, which limits the practical use cases. Whereas with optic fibre, light reflection and refraction results in very low energy leaking, and what leaking that does occur can be solved with repeaters, and thus optic fibre is used for data cables long enough to cross the entire planet. The two advantages that electrical cabled methods have are: for optic fibres, the signal has to be transferred from electricity to light and back to electricity, and thus USB/ethernet/TB3 are much simpler and cheaper for short distance connectivity; and they can transfer electric power, whereas optic fibre can't, and in fact the hardware that translates the signal from electricity to light and back again need a power source.
And thus for data:
Optic fibre is king for speed and distance.
4G/5G is king for mobility
Ethernet/USB/TB are king for short distance connectivity and power supply.
I know this didn't exactly answer your question of "Can this be used to send internet to households instead of fibre", but it does explain why we use optic fibre so much for fast internet.
