Why is it "people are willing to pay" and not "corporations are brazen enough to charge"? These utilities are necessities and relatively few people have access to cheaper alternatives to them.
Because, under usual circumstances, self-interested corporations compete against each other to get as close to what people are willing to pay for energy as possible.
There’s a reason most universities don’t hand you a bachelors degree in economics as soon as you complete EC101. You should look into EC102 and the rest of the curriculum.