So what, it raises the waiter minimum wage from $2.50 an hour to $7.25 an hour? When the average waiter is making / expecting $10-$50+ an hour, it's still the situation OP describes where tips make up the vast majority of their pay. There are restaurants that do the higher prices no tips thing, but I am not aware of any states where you can show up at a random restaurant and get paid $30 an hour to wait tables?
Minimum wage in Oregon is $11.25/hr with no special considerations for wait staff. Tips are always on top of the hourly wage and do not subsidize the wage paid by the restaurant.
Having never been to Oregon: the interesting follow up here is, are you as a customer less incentivized to tip with this knowledge? As a Texas resident who has worked in food service in the past, 20% is near obligatory barring subpar service (Texas is one of the states that pays $2.15 an hour for waitstaff).
