I'm close of doing that with my Mom. The only reason I haven't yet is because I'm sure she would commit suicide. My older sister, however, has done it. Throughout all of our lives, my Mom barely took care of us. She, countless times, forgot to pick us up at school, to cook for us, to buy basic needs things for us, never cared about our education and progress at school, etc. That all started after she divorced my Dad. I was five and don't remember much of it, to be honest, but my sister does and it's incredible what she had to put up with during her childhood (if you can call what she had a childhood). My sister had to mature so fast and ended up taking the role as my "mom" until I was a responsible adult. After the divorce, my Mom had several boyfriend and only cared about pleasing them, going out with them, always putting us in second, third, fourth place. She's the biggest liar I've ever known and she only cares about money - especially my Dad's money... Oh she was good at ripping him off...-. At age of 19 my sister had a 3y relationship going on and, for the 100+ time, my Mom told her to leave the house (a better way of saying: kicked her out). This time, she complied. My sister got married and moved away with the husband and sacrificed her education at university, she had to transfer and it took much longer to finish. However, that still wasn't the reason why my sister had completely cut off contact: this happened in the beginning of the current year when she gave birth to my twin nieces. My Mom didn't want to visit and be there for the birth but ended up going, and it was a disaster. The coming of children should be a happy and harmonic period and my Mom made it a living hell. She stayed at my sister's until the birth and behaved in an extremely jealous and selfish way, showed no interest in being together as a family, smoked the whole time and did not help with house duties and taking care of my sister. To finish the act, right after the birth she went to the airport and traveled back home without telling anyone. Oh and I forgot to mention that she's a heavy smoker since she was 15 and did not stop smoking when she was pregnant of both me and my sister - it's a miracle we don't have any problems because of that. Before I moved to the United States she did the same to me: kicked me out of the house for reasons I will not go into. She does that to everyone in her life, she loves drama and trouble and that's why she's now alone. I was close to cut the cord too, but she will kill herself if do it, I'm sure.
Now she's found that she has inoperable metastatic lung cancer and is seeking for forgiveness. That is sick. Using a disease to manipulate people around. And knowing her so well like I do, I wouldn't doubt that she could be lying about how serious the cancer is just so she gets more attention.
My Father, tho, is our real hero and likely the reason my sister and I are decent human beings.
TL;DR: my Mom is a horrible person.