Making a per order tax/fee isnt the right method to achieve their goals, and actually hurts these delivery drivers. To write a living wage law, you need to look at the income not a fee/tax on the task performed.

Thats why route delivery (like grocery/elderly meal delivery/lunch runs) can keep the costs down.

Truck drivers are also having lots of issues with lowering incomes also, and corporations are trying to push the expenses on them. Another area you need to look at the entire model and figure out how the truck driver makes money and what is hurting them. (dispatch services, gas prices, insurance, lines, etc)

Long wait times are hurting many delivery type services with rising expenses.