I'll agree with both sentiments that this is a very important life skill, but also one to apply carefully.

My relatives are made up of a lot of manipulative, sociopathic and occasionally violent people and I cut them off no-contact when I went to college. In a lot of ways, this was the best thing I've ever done. But there are consequences to this that no one tells you about, and one of the ones I'm struggling with most is the loss of memory and identity of my first 18 years. No one from that time is in my life any longer, and now it feels as though those years didn't exist at all.

On the other hand, I feel like I'm free to develop a personality of my own now - before I was so caught up in their problems that I barely had one in the first place. My life now is worth the destruction of the old one, even if I had no way of knowing for sure at the time.

Basically, just know your own situation and what works best for you. There are times to end relationships, ones that are so beyond salvation that they're killing you, and times where you can attempt communication first and slow down a little. Knowing the difference is still something I'm working on.