A service does not have to be a monopoly to be classified as a utility, nor does it have to be life-threatening if inaccessible. Mobile phone in my country is provided by 4 major independent companies (and this isn't the US but a country with only a few M people, so 4 big providers is a pretty good number) and they are still required to allow free transfers of numbers to other providers.
> One cannot live without a utility...
If my water got shut off, my life would go on pretty normally - drinking water is cheap in stores, bars are required to provide it free of charge and I can shower at a friend's place or something. If I lost my email account however, I'd have months of work ahead of me just to restore my digital life to its previous state and my livelihood would be at risk. All bills go to my email so I couldn't pay for the services I and my business need, business partners wouldn't be able to reach me, neither would my customers... In fact, I can't really think of any other single thing that would cause more problems if lost than my email account(s).
> One cannot live without a utility...
If my water got shut off, my life would go on pretty normally - drinking water is cheap in stores, bars are required to provide it free of charge and I can shower at a friend's place or something. If I lost my email account however, I'd have months of work ahead of me just to restore my digital life to its previous state and my livelihood would be at risk. All bills go to my email so I couldn't pay for the services I and my business need, business partners wouldn't be able to reach me, neither would my customers... In fact, I can't really think of any other single thing that would cause more problems if lost than my email account(s).