We only had the internet for what? 20 years? I don't think humanity as a whole is already that reliant on the internet that it cannot go back.
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With out internet or computers ...
I have no bank account, and no way to get/spend money.
I have no way to prove I am why I say I am. [*1]
I have no way to get to my job. [*2]
I have no medical records, and no way to get medical insurance coverage.
*1 - In the US your identity is ran through several governmental databases .
*2 - Modern cars have too many sensors and computer parts to operate without them. Bicycles have a limited range. (( I'm sure SOMEONE will eventually suggest riding horses to and from work ))