The article initially does a good job of describing the situation, but gets a bit confused when it gets to the history of the US, especially this line "This is what happens when you let natural monopolies operate without oversight." What it's discussing is not natural monopolies; it's discussing public utilities which are granted monopolies expressly through regulation, not despite it. Also, the US has a lot of oversite on wired ISPs. The prices are almost always approved by regulators.
A good example of a natural monopoly is Google search. It's pretty common for people to get frustrated by it, and look for other search engines. There's also multiple companies trying to compete with it. Normally this would mean that users would migrate to the competitors, but Google's search algorithms have been so good that practically every user has stayed with Google.
Natural monopolies are still easily disrupted, if the naturally-occurring barrier changes. For example, Internet Explorer had a natural monopoly, due to Microsoft's "embrace and extend" strategy giving it many capabilities that other web browser didn't have. When the internet market quickly migrated from a feature-first market to a security-first market, Internet explorer was quickly overtaken by Chrome and Firefox. There's a reasonable chance the same thing will happen with Google Search, as the market for it's search algorithm is overtaken for the marked for LLM based web searches, which Google is pretty bad at.
Anyway, the reason Comcast or Charter is the only one that provides cable internet in your area isn't because it's too expensive for anyone else to deploy cables. At the margins they operate, it would be well worthwhile to invest in a parallel infrastructure, but it's downright prohibited almost everywhere in the US. In fact, they may own the rights to lay cable, despite having never laid any. This is the case where I live, for the phone company, which plays by similar rules.
Fixed-wireless internet providers are starting to provide some competition, as backhauls have improve enough that cellular providers can compete with wired internet providers. T-Mobile is currently offering $20/mo fixed wireless add-on plans, with a five-year price guarantee. To complete with the fixed-wireless market, Comcast has launched a service called NOW Internet, which starts at $30/mo with a similar price guarantee and no no add-on requirement.
Speaking of "starting at", a large source of high prices is the common use of FUD to pressure users into paying for more than they need, or can even use. Very few households peak at more than even 40 Mbps (https://www.wsj.com/graphics/faster-internet-not-worth-it/) and the starting price of almost every provider is above that, but must customers have been talked into higher-tier plans.
The only web hosts that regularly provide data faster than that are video game distributors, so if you are in the type of household that would like to download game updates in minutes, instead of tens of minutes, while also watching multiple 4K video streams, then comparing other plans may be worthwhile, otherwise stick with the absolute cheapest plan available from all providers that serve your area. (And, if you are big on multi-player gaming, selecting the ISP with the lowest latency will be beneficial, but all plans from a given service will be the same latency.)