I don’t really agree with the idea that some people are “toxic” while others are not. I think most people, especially marginalized people, have skeletons in our closets and some degree of abuse in our pasts. That can all make us defensive, sad, moody, and sometimes less than fun to be around.
I think the key difference is some people are working on our shit, whatever it may be, and others are not. People who want to have conversations about miscommunications or pain points can usually muddle through, I think. People who refuse to change or acknowledge their behavior might be a problem can only handle partners who agree with them and indulge them in everything. I wouldn’t call that toxic, just antisocial.