Constraining the discussion to America, you’d be far more wrong to assume someone doesn't use the internet[1][2] or a cellphone.[3][4]
[1] http://www.pewresearch.org/fact-tank/2018/03/05/some-america... - Only 11% of American adults don’t use the internet. Of 18-24 year olds, only 2% don’t. 2%. Holding narrowly onto your assertion, the numbers are higher for poor, rural, elderly and non-high school graduates.
[2]http://www.pewinternet.org/2018/03/01/social-media-use-in-20... - 68% of adults use Facebook. 73% use YouTube. Looking at 18-24 year olds, 95% use YouTube.
[3]http://www.pewresearch.org/fact-tank/2017/06/28/10-facts-abo... - 77% of adults own a smartphone.
[4]http://www.pewinternet.org/fact-sheet/mobile/ - 95% of adults own a cellphone.
Shopping at mega corps? Well, it’s well documented that Walmart has done a good job of decimating local economies and there is definitely a homogenization of retail options in the US - but even if you don’t shop at one of them, if you use a credit or debit card, a mega-corp is tracking you. Doubly so if you use a smartphone.
We are already there.
3-letter govt agencies can listen track your calls, intercept your browsing and read your email.
Unless you pay in cash and shop only at your local mom and pop shop, your purchases are already being tracked and reported.
Your cellphone carrier is selling your information to third parties.[1]
You may not be on Facebook or WhatsApp but all your IRL friends and family are. They have your phone number in their contacts list and they have shared it with Google, Facebook, Twitter, Linkedin and God knows how many other companies. They have taken your pictures and tagged you.
Other than a very small number of privacy-conscious people, which includes living-off-the-grid doomsday preppers, the rest of the country is already there.
1. https://www.csoonline.com/article/3233211/security/mobile-ca...