Well then you have weak imagination. No large dictator went out willingly, all who killed tens of millions thought they are on some holy mission for greater good and just squashing the enemies of this greater good.

Death is great, frees up limited resources, removes old farts who think they know how future for everybody should look like without actually having a good reason why.

Lets expand reasonably at least around out solar system first (meaning say >50% of human population not on earth), and then start looming into immortality.

Show me 1 truly powerful person in the past who wasnt an arrogant self centered a-hole.

We talk about enslavement of whole human race potentially forever in worst possible case. If that is something you can ignore, well I can't.