But what if many people actually wish to be slaves, wish to be forced into service?

If people are on the whole content to be forced by other people (say, by the govnerment) into doing things for their own good against their will, then why didn't prohibition work? Getting people to stop drinking so much alcohol was clearly going to create positive utility all around, right? So why did people resist so strongly against that loss of freedom?

Your religious argument is interesting, but frankly that's a whole other conversation; it does seem to be possible to get people to do something "good" by convincing them that that's what God wants them to do, but that's really not the same thing as using actual force.