Besides a data cap in some areas, it's not really metered, not a variable bill like water or electricity if you wfh

The point is - they have different plans at different rates (prices) and they base it on what they believe you use it for. So you can’t just be dismissive of someone thinking that internet access for someone who works from home might cost more than if you don’t work from home. It may be wrong but it is logical and possible in the usecase/context being discussed