From this I conclude you believe some things never found in "that logic":

a) Slavery improves societal happiness

b) Maximizing happiness justifies coercion

Thankfully most people don't share your values.

That to me looks only like an observation, not an argument in favor of anything in particular.

Personally speaking, I would not be happy if 1% of my fellow citizens were tormented so that I along with my 99% cohort could be happy, paradoxical as that is.

Let's use the observation to understand what's happening in our respective societies and make things better for everyone.