Airlines are a poor analogy
Sometimes I want a cheap flight so I fly EasyJet or Ryanair, other times I need a convenient flight so I go BA or whatever. The distinction here is that I am free to choose whichever airline I want for each flight, but with the typical UK ISP I am saddled with a one year or even two year minimum contract. Given that ISPs are utilities just as much as gas and electricity companies, when am I going to be able to switch whenever I want with no penalties?