I'm going to cut someone out of my life at a moment's notice with no explanation to them.
Why would you cut them out of your life?
Explaining things to them wouldn't change anything so this is the only option.
It's obviously your decision whether you stay in contact with someone, but cutting someone out of your life without telling them why you're doing it is very rude to them. If you talk to them and explain things, they might be willing to make changes. At the very least though, you can end the relationship without feeling guilty for ghosting them.
Don't care about other people. They are just meatshields.
Well you should care about other people's feelings, it's important to have empathy towards others.