Almost all of any potential increase in total speed will have to come from using new parts of the electromagnetic spectrum. To that end the FCC is kicking out old users from the 3 GHz range and auctioning it off to the mobile telcos. This includes both the traditional backend media distribution role and completely eliminating the amateur radio alloacations (ref: https://docs.fcc.gov/public/attachments/DOC-360941A1.pdf).
But even with stealing bandwidth from you, me, and the normal media companies it won't replace an ISP with wire. Why? Every single wire or fiber has as much bandwidth to itself as the entire electromagnetic spectrum useable in freespace. And you don't have to share. Wireless, no matter the modulation, can never replace wired ISPs simply because there's not enough spectrum for everyone to use it at once.
Additionally, the 3-4 GHz spectrum really doesn't have that good of propagation characteristics. And mm-wave, well, that's about as effective as a light post light in terms of coverage area.
No, 5G will not destroy any monopolies. That's silly.
The reach can be increased for <50$ to at least a few hundred meters radius.
Why not use Wi-Fi at this point?
Radio technologies have strengths and weaknesses. While WiFi works great in a home, other radio types are better at transmitting data long distance. The best solutions combine a mix of radios to leverage their strengths.
This is the problem mesh networks have to solve: height. Everything else is cheap and easy. But without height above terrain and line of sight it simply won't work.
From a technical perspective, there's definitely been mixed reactions to the effectiveness of 5G technology. That's another topic in and of itself, though.
Over the air carriers have much broader latitude to block and prioritize traffic than the wired ISPs do. They also have an absurd national security justification to build out 5G local infrastructure without any input or regulation from local authorities.