Due to the oligopoly of service providers (at least in North America), many areas only really have 1 option for true high speed service if they even have one at all. Switching providers isn’t an option. And in the unlikely event there is more than one option available, if one sees the other getting away with certain shady practices such as throttling, they’ll do the same in order to cut costs and increase profits.
Sure, some areas may have several smaller local “resellers”, but they tend to run on the big local providers’ networks, and are subject to the same levels of service, including any throttling the big provider may have to save on their bandwidth costs.
So yeah, switching to another provider is not an option at all for the vast majority of folks in North America.