1. The Internet isn't neutral to being with. To get connected to the Internet an ISP, especially a smaller one, will have to buy transit. But can also make peering agreements with other, often local, ISPs and large services like Google or Facebook. In reality, depending how things are connected, your connection speed will vary regardless based on business decisions. Net neutrality leaves those decisions up to, other, big players like large (tier 1) ISPs, cloud providers and big services instead of consumer ISPs.
2. The real problem isn't net neutrality, but competition between consumer ISPs. Net neutrality restricts the business model for ISPs even when there competition. Many consumers might actually just want news, social media, software updates, some streaming services and limited access to the open Internet. Yet, they are forced to pay for the rest of the traffic and infrastructure.
3. I used be a nice idea that the Internet was open and that most nodes where equal, but that isn't really the case anymore. There's a number big players with huge influence over Internet technology that makes a lot of money. While consumers pay just to access the Internet, don't get static ip addresses and limited upstream traffic. Internet protocols have not kept up with reality and hosting your own services are challenging with the prevalence of ddos, spam, ransomware, exploits etc. You can argue that the big services that makes a lot of money should today be, or at least have the possibility to be, paying more. Especially since they enjoy economy of scale.