We don't need hypotheticals to know what killing net neutrality can do:
Do you like Pearl Jam? Without net neutrality rules, AT&T censored their livestream after Eddie Vedder criticized then-president George W. Bush. AT&T also blocked the usage of Apple’s video chat service, FaceTime, in their network, so that customers would have to pay for more expensive data plans. Verizon blocked messages sent by abortion rights group NARAL, saying that their content was too controversial.
For extremes, look to other countries: