Cast your mind into the future.
So, we’ve killed off all of those evil Muslims/Christians/Hindus/Jews/Liberals/Fascists (delete or replace to your preference.)
It is a pretty big world though so are you sure you’ve destroyed every single scrap of evidence of those people and their beliefs? Did you in fact actually kill every single one of them off? Are you sure? Have you finished now or do you now need to obliterate or convert everyone else?
If not, however small the seed, how will you stop it growing again? Even if successful, can you be certain that future human brains do not follow similar paths and generate those ideas again under differing names? The original basis for such beliefs came from the minds of humans after all.
That is the lesson from history many are missing.
This is not a ‘liberal’ opinion. This is something understood when allied with education and wisdom and applied against past and future history. Appreciating it will stop you being influenced by those who pretend such an outcome is possible and beneficial.
Look at your family and those you love. How many of them are you willing to sacrifice to achieve what you currently see as right, even if it is simply sitting in comfort whilst the world burns? How many hundreds of millions of lives lost are worth reaching a point you are happy with? Is it worth risking the very existence of humanity to find out?
Think hard because the other lesson from history is that being in a position to say “It wasn’t worth it”, is too late.