Economists like to pretend that currency is entirely rational, real, finite, and concrete, but it’s really not. That fiction only holds together as long as the bulk of people are willing to believe it.
Besides, these laws would never be two lines long like are written here. They would have addenda and provisions and such, preventing businesses from discriminating against employees based upon commute length, giving an upper limit, preventing a decrease in compensation to accommodate the commute benefit, and so forth.
And in the end would it turn out to be less than worthwhile? Maybe. But current remuneration in Western culture emphatically isn’t working. We need either one big change or lots of little changes, and this would fall in the latter category.