How would you compensate employees for commuting to work?
Suppose there are two employees: Alice and Bob, who do the same job at the same factory. Alice has a 10 minute (20RT) commute, Bob commutes 35 minutes(70RT).
If you're the owner of the factory, would you compensate them for their commutes? How would you do it?
But that's not what compensation for the commute would incentivize. I don't understand why people think getting paid to drive to work would mean employees would spend most of the week driving. It would mean employers would only hire employees who live upstairs.
If someone enjoys driving more than their actual job, and they're getting paid to do it, it's arguably an incentive. At the very least, you're no longer decentivizing the commute by paying for it.
Paying money for a behavior is an incentive for that behavior.
Does that mean every employee would choose to live far away to maximize their commuter mileage benefit? No.
Does that mean some barriers to living far away would be reduced, thus increasing odds that some employees would live further away, or that some prospective employees that live at distance would consider applying to this company over a company that doesn't offer a commuter mileage benefit? Yes.
Companies also aren't worried employees "would spend most of their weeks driving". Most companies don't include drive time as hours worked.