The cancer isn't deregulation or regulation but rather regulatory capture.
Making the barrier of entry to the market so high that nobody can compete with existing players. Nearly every dysfunctional market in the US could be made better by deregulation, not because regulation is bad but because it's badly regulated.
You have to understand that some things can not be different. Lets take an example that is simpler, that even libertarians might understand: Streets, you can not privatize streets. You can not have a market where companies build streets and compete for customers to use their streets. Because you can not build 5 different streets to the same place. Infrastructure like fiber internet is like streets, you can't have 5 different companies rip open every street to every house and put fiber into it.