Without the internet you cannot function well in the economy - many many deals (including those for utility companies as well as retailers) are only available either online, or if you found them online and then mentioned them in the shop/on the phone.
The internet is an information network that gives consumers nearly perfect information about price; which translates to a much more ideal market (in economic jargon,) which is much more efficient. It is essentially a utility, if people without it are at a significant economic disadvantage like that.
You conveniently left out the words "high speed." Everything you talk about can be done just fine even on the mediocre broadband speeds that people in this thread are complaining about.
"high speed" can be swapped out for "high quality" in this context.
Spotty connectivity, packet loss, frequent disconnects - all things that come with shoddy internet infrastructure. High speed generally means higher quality.
And let's not forget that even just for work the internet is not only used to send plaintext emails. We video chat, we work with crappy bandwidth-hungry web apps, and those are just the smaller of the hungrier things we can do. At my work I have to download tens of gigabytes of foreign data every few days.
And as someone who works at home and manages a work-entertainment schedule to keep sane, it's pretty pathetic to see people try to squeeze out an "Admit it! You just want a faster netflix!" from others. So what if they do? If you compare internet access to access to drinking water, then high speed internet access is drinking water that doesn't taste like piss. Just because you can live off it doesn't mean it's pleasant.
If all you're doing is moving text around then faster internet isn't going to help any. Unless you're streaming video or doing a few other high bandwidth activities then even really shitty broadband is going to service your needs just fine.
Nobody is only moving text around, occasionally (how often depends on the type of work) you need to move a lot of data. In that case a low speed connection stops you in your tracks.
But who just moves text around? Work frequently requires the use of Hangouts, Skype, GoToMeeting, Dropbox, etc. If you have to work through a VPN, the latency added by poor service is a serious drain on productivity.
The internet is an information network that gives consumers nearly perfect information about price; which translates to a much more ideal market (in economic jargon,) which is much more efficient. It is essentially a utility, if people without it are at a significant economic disadvantage like that.