The most astounding thing is that the people who are so confident that their current understanding of morals is absolutely correct and there is no possible reason to debate it or challenge it were, not very long ago at all, just as confident and vehement about things that they now consider morally abominable. This is very obvious in rapidly-changing areas like trans rights, where you can see people insist that only evil bigots would be uncomfortable with trans activists beating up elderly lesbians just for holding views that, only a handful of years earlier, the same people insisted it was bigoted to even criticise in any way.