I have a colleague living in the northern California wilderness who maintains a point-to-point wifi antenna at the top of a 300' redwood tree because he needs to use a WISP rather than an LTE provider to get uncapped data. I just looked at these plans and they look like a dream come true for him.
T-Mobile is currently targeting areas where they have excess capacity, but their capacity will be growing a lot over the next year or two as they launch a lot of new mid-band spectrum. Verizon is also looking to launch new mid-band capacity, however that will probably be a couple years behind given that the spectrum isn't currently free and the fact that Verizon's new spectrum will require more towers for coverage. Still, wireless companies are looking at a lot of new capacity and looking to expand into home internet.
Sometimes it's about the technology coming together at the right time to offer a new product. Think about the original iPod. Before then, MP3 players were either sad 32MB players that could only handle 10 songs or large and heavy boxes that weighed a pound and couldn't fit in a pocket. Then the 1" hard-drive came around and Apple shipped the iPod. Without the 1" hard drive, Apple couldn't offer a light-weight, pocketable music player with a 1,000 song capacity.
Likewise, without new mid-band spectrum and new 5G technologies, it's very hard for wireless carriers to offer home internet without data caps. However, those new technologies come around and all of a sudden it opens new opportunities. T-Mobile has already started to use some of that new capacity. Their base plans include 100GB of premium data (deprioritized when the network is busy after that) and their new MAX plans have unlimited premium data (never deprioritized).
The industry will be working toward home internet over the next 5 years, but it is a reality today for a lot of customers and that will start growing quickly.
DSL will become the antique thing since you can't go much more than 50 MBit/s outside of urban areas with short distances due to piss poor old cables, while DOCSIS can already deliver 10 GBit/s over way longer distances because the shielded cable allows way more effective transmission.
Upgrades (aka splitting the trunk to provide more bandwidth to the customers on one branch) are relatively easy to do, whereas upgrading 5G capacity is a legal hellhole - you need permits, pay rent to whomever's house you're setting up the cell, and the base station and antenna hardware is expensive.
Don't get me wrong, 5G will be extremely useful for rural areas as it's way cheaper to build out than wiring up houses with DSL/cable... but where there is cable (and the cable is somewhat-ish affordable), people will choose cable over 5G.
I think you may be surprised. In my old area, people are leaving Comcast in droves for T-Mobile's 5G service, not because it's all that much better or all that much cheaper, but because they've been taking it from Comcast for two decades now and they finally have an opportunity to show their displeasure.
Verizon has also announced that it's looking to cover 50M households with home broadband in 2024. While not as ambitious as T-Mobile, that's still around 40% of households getting new home broadband competition.
I'm less confident that coax will go the way of POTS. DOCSIS 3.0, 3.1, and 4.0 can offer pretty decent speeds and the networks are already built. I think the coming competition will push DOCSIS-based systems to actually offer better service. Comcast can and does offer gigabit service today, but they tend to charge a lot for it as a premium service.
While I'm very bullish about wireless home internet (especially as carriers deploy mid-band spectrum with T-Mobile leading the way in 2021 and Verizon and AT&T following in the 2022-2024 time-frame), I think we're still going to see certain limitations with wireless. I don't think that will matter to most people. Most people just want to be able to stream video, Zoom, etc. They don't need gigabit speeds. Heck, 5 HD video streams can fit into 25Mbps. Even if wireless home internet won't be a great option for some power-users, the fact that it will be an option for so many people will make it a lot harder for cable companies to be mean to their customers.
I think it's also likely that a lot of people will end up seeing 2-3 wireless broadband options given that there are three wireless carriers.
Maybe you live in a Fios area so you feel like there is competition. I wish I lived in a Fios area. For so many people, wireless home internet means getting another competitor (or another 2 or 3 new competitors). I have access to Verizon DSL at 3Mbps. I can't leave my cable company for that. I could leave my cable company for wireless home internet in the 25-300Mbps range.
The problem comes down to spectrum, how much power you can push across that spectrum, and how you share that spectrum with other devices. The more bandwidth you have available, the more power you can send across it, and the fewer devices you have sharing it, the higher your information rate between a sender and receiver.
5G, in theory, brings a lot of spectrum to the table, so they can talk about, say 1 Gb/s or 10 Gb/s connections. The problem is, you've got to find a way to share that among users. Sharing spectrum is never a 1/n process because of inefficiencies, so you end up with a bit under 1/n speed for n users.
Meanwhile, cables might have less spectrum, but you can push comparatively more power through them, but more crucially, everyone gets their own connection and there's much less noise. So, more aggregate bandwidth across cables than over the air.
This is all very handwavy, so if someone would like to put some numbers to this and/or fix any mistakes I made, please have at it.
Technically, everyone on the same cable node shares the same spectrum (typically targeting 200-500 subscribers.) Which is effectively 1GHz at the moment, a decent chunk of which is dedicated to TV.
But certainly there's less noise, neighboring nodes effectively don't interfere with each other, and nodes can be made arbitrarily dense.