Many people also seem to forget that not everyone has a dedicated room or otherwise extra space to work in. Sure, if you live alone it doesn't matter but with other people living in the same apartment/house and perhaps them also working remotely, you suddenly need extra space just for good working conditions. Working space has a cost, be it in an office building or at employees' homes. Also good ergonomics means one needs a good desk and a great office chair which are not cheap to buy. Sure, I wouldn't necessarily demand more pay just for WFH, but I would never ever ever take a lower compensation in exchange either.

That said, I love working remotely from home and wouldn't go back to office. It's just that even if you save time and money in commutes, there are other costs in place that wouldn't otherwise necessarily exist.