Those are the wholesale prices to the utility company itself from the grid operators, not the prices to end users from the utility company. End users pay a flat amount per kWh that does not change by demand.
Most of us do. A few people do sign up for variable rate plans, and they did get astronomical bills during the snowpocalypse. IIRC they didn't get any aid or anything, it was a small enough number of people that they just got hung out to dry.