The issue there is 'define good'. You and I agree that mass murder isn't a good thing but that doesn't mean it isn't worth debating. You and I might agree that the Black Death is a bad thing, because in the short term it certainly is.... everyone gets ill and dies of coughing themselves to death. But this is the beginning of democratic mandate and the Magna Carta. We'd likely agree that World War I was a mass murder waste of life, but it led directly to an improvement in the lives and rights of women.

There is strength in considering the counter factual, because agreement at the outset is often too simplistic.

Yes, you're right I did say 'everyone being in agreement' - that's my bad, but how do you determine the difference between everyone being in agreement and everyone seeming to agree when the dialogue is heavily policed? That's what a lot of people spend their time doing.

And yes, some people can stand down when they realise they're made a mistake but that's much easier to ask the other guy to do than it is to do so yourself. I found this out when I argued the centre ground on the Roe v Wade argument and noted that the legal situation was implemented (somewhat unfairly) by a liberal supreme court acting outside of its role and function.

https://medium.com/lucid-nightmare/alito-is-right-roe-v-wade-does-need-to-be-overturned-108a8e36c61