Yes, true actually. We are mixing different levels here.
Endurance
Toxicity
Abusive
These are entirely 3 different things. Like different level.
For a relationship to work out, I agree with you sometimes, certain level of endurance is necessary.
Toxicity can be generated but like an early stage cancer, in-time detection & resolving can save the relation.
However, Abuse is a red-flag and no discussion, no endurance or nothing to resolve. It's the final, ultimate stage cancer.
You damn quit.