NN is not about traffic management per se, it as about traffic management for economic benefit, you aren't the only person to not understand that, the new EU digi commish doesn't understand it either.
NN is not about limiting bandwidth to spewtube because the ISP doesn't have the upstream bandwidth they have "sold" to their customers, (which is bad, but another story, change your supplier) it's about when they limit the badwidth because vimyo pay them to prioritise streaming to their site.
In the UK, Sky, the TV company run a major ISP. Without NN, they might de-prioritise traffic to Netflix. Why, because they want the service to appear poor, even though it isn't and moneytise their ISP clients getting them to trial NowTV, an OTT video outfit owned by Sky. NowTV would then appear to offer a better service to the user than Netflix, because the service to Netflix has been artificilly degraded by the ISP's traffic management system.