Economically no problem with that race, of course it eventually means cutting out the human driver and usually people who can only drive are not really ready to get a different job. They have no other skills that are "in demand".

A race to the bottom means cutting quality (e.g., cleaning frequency and thoroughness) to reach the lowest price.

So long as there's multiple providers, if one of them gives a filthier, though cheaper, service, there's definitely people who will prefer it.