All the reasons you gave are commonly the reasons. There’s also the thought that being with someone else or being alone is not going to be better. A psy told me, “You probably never would have been happy with anybody.” So, the problematic person is me. I’m lucky anyone stays with me. I’m the toxic person.
Growing up, I broke up with guys who weren’t compatible with no trouble. I didn’t have toxic relationships. It was in my 30’s and married that things went south and have been on a downward spiral for 20 years now.
I just got called toxic (my husband was too) by our son. He said he doesn’t want the negative energy in his life we gave him over the past year. But, see, he turned it all around to suit him. He was on the offense. We were on the defense. It was really he who was what he accused of us. That’s what people do when their intentions are to be hateful and cruel. I hope if his relationship is toxic, he will find the strength to leave. His parents were sacrificial lambs.
So, we tend to think the toxic person is ourselves and there’s no real escape, just jumping from the frying pan and into the fire.
When it’s bad enough, we run. Physical harm is enough for some to motivate, while they will endure endless psychological harm.