For me it depends on the partner and how things ended. I've had two partners and they were both anxious, depressed and had very poor self esteem. One of them took that out on me, and the other took it out on himself.
I'm still in contact with/tentatively dating again my ex-boyfriend. He was the one who tended to punish himself for his issues, and while him breaking up with me was devastating, it wasn't explosive and we ended on relatively good terms. Since I recently reached out to him we're back to daily contact and things are going well...though it's really too soon to tell.
My ex-girlfriend, however, I am no-contact with. Mostly on her own request, since she blocked me, but it's honestly best for me too. Even though I miss talking to her as she was one of my best friends for fifteen years. Once we started dating she became controlling, weaponized my autism against me, convinced me that I was a horrible, abusive person with anger issues, and then (after I told her we needed a break because her constant attacks had me on edge) she deleted all of our stuff, we used to write fanfiction together - this was fifteen years worth of writing, and said we can never go back to even just being friends again because I was too awful and made her life hell. She nuked that bridge hard.