Your assertion that distributing costs among many customers is a form of slavery seems really disconnected from actual slavery.
Many times, businesses pass costs onto customers for things they don’t use. My college charged me a “sports fee” for games I never went to. My health insurance will charge me my premiums when I don’t get sick. I will share the cost of peaker plants even if I don’t use electricity during peak hours.
If the utility covered some of these costs, people who didn’t like the resulting rate hike could buy solar panels or a generator.
In contrast, the word “slavery” refers to a practice where someone is kidnapped and forced to perform actions (labor, sex acts, etc.), often under the threat of having “the shit beat out of them,” to use a colloquialism.