The commute can optionally be replaced by other activities with a bit of diligence. Personally, I'll go for a run mid day. I know others that will go for a walk in the morning and after work. Others will perform some other task to decompress.

It's all about what's knowing what's best for you. If you need to get in the car and sit in traffic to decompress, you still have that option if you WFH. But just like commuting takes energy, so does getting up and decompressing in a way that is beneficial for yourself.