Washington State changed the minimum wage years ago and mandated it to include tipped workers. It didn't really change the tipping, but the tips still went to the staff, so at least the workers got a more livable income out of the deal.
Tips will be mostly irrelevant once patrons are not shamed and manipulated into paying tips. If the salaries are already paid, most people will not tip.
Tips finally got to a breaking point in the US and they're on the way out for good.
This is true, in Illinois. However, restaurants can do whatever they like with "service charges", though customarily those go to the service staff. Automatic gratuity is already illegal in Illinois, or at least illegal to enforce, so a lot of restaurants already apply a service charge on large parties... easy enough, and perfectly legal, to expand that and claim it as revenue.
And that's just the legal route. Wage theft is rampant in this industry, at least in Chicago.
Source: Am current server in Chicago for over decade.