There’s a long history of neutrality regulation for networks – going back even before the internet – even though the requirements have taken different forms over the years. And when those regulations were enforced they ended practices that hurt consumers and companies that wanted to provide services over those networks. Here’s a great summary of the history: https://www.wired.com/story/how-the-fccs-net-neutrality-plan.... The current net neutrality regulations under Title II are strong and address the many forms of discriminatory (i.e., anti-neutrality) conduct we’ve seen in the past.

I have to respectfully disagree with a premise in your second question, that deregulation is what would allow for more market competition. The history clearly shows that when neutrality regulation was in place and enforced, it increased competition, for example: in 2005 it protected VoIP against discrimination by a phone company with a competing service; in 2008 it protected online video against discrimination by a cable company offering cable video on-demand. Moreover, ISPs invested in broadband infrastructure over the years because net neutrality was protecting edge providers, which led to huge innovations like online video, which in turn helped drive ever greater consumer demand for broadband that justified further infrastructure investment.