I do think a proportion of estrangement is carried out by people who are spiteful or have a grudge to settle, or an agenda.
My sister decided at age 45 that my she no longer wanted to 'deal with' our parents who ARE and have been fairly abusive. So she went into an online group, learned all the key words: toxic, co-dependant, flying monkeys..etc...and came out with a plan and advice on what steps to take to estrange herself and her kids from them, so that SHE could 'heal'. I told her I didn't agree with all that, that she could quite easily work on how to deal with their personalities, just like she will expect HER kids to be able to deal with her personality when they get married and have kids....but no.....she started to go the route of telling me I was in some way...enabling them. I don't enable them....if they do something I don't like, I have it out with them there and then. And that's that. I don't do what she's doing, and brood, and overthink and decide that she is fairly perfect and everyone else is toxic to her life.
So 2 boys have lost the opportunity for any meaningful relationship with their grandparents. I find that very hard to bear, for the boys and for my parents..
Their other adult child, my brother...hasn't spoken to them for 25 years. They 'fell out' over something very trivial and he's never bothered to get back in touch with them. The mother of his kids binned them off, again...because they were 'toxic'. Again tho, she has to hope that when she's their age, that her kids or kids partners don't ambivalently and selfishly bin her off...for no real reason.
Estrangement isn't the answer unless the person being avoided is very very seriously awful. It shouldn't just be because: you don't like them (esp if there are kids involved), you've managed to label them as 'toxic' (but remember, there are NO non-toxic people...everyone is a complete pain, to some degree), you feel 'disrespected' by them, you have a grudge that you're trying to settle....etc etc...
The supposed peace of mind for one person, isn't worth the suffering for so many other people involved, imo...
My dad is actually not talking to me at the moment, called me all the names under the sun because he thinks I've not encouraged my daughter to stay in contact with them. I forwarded him an email I sent her only 5 days ago, telling her to make sure she tries to stay in contact with them. He STILL is saying that I've made no effort. I have made regular effort, over 15 very long years. So I'm now being estranged from my dad by my dad, because someone else encouraged my daughter to become estranged from my mum and dad (ex-husband, to settle the score from me leaving him).....while trying to deal with my own estrangement from my daughter (again, due to ex-husband settling a score).. Even tho my dad is estranging me in the cruelest circumstances ever, I'm never going to not be there for him. I understand that, perhaps he cannot comprehend that my ex-husband could be so manipulative.......dunno.....but I am not going to be dumping anyone....not my parents, not my daughter....heck, if the ex-husband wanted to become friends, I'd welcome him....even tho he's caused immense pain to me, and massive financial loss also.
Life is too short FOR estrangements (apart from in very very ultra severe cases)..