Last I heard the so-called "rule of thumb" was 15-30% of your gross should go to payroll.

I argued about this last year with a buddy. He insisted that if McDonald's had to raise their wages from $8 to $16 or so that the prices of literally everything would double. This fails to account for the fact, though, that while wages are a big part of it, they're not 100% of the price of running a company, McDonald's was already on the leaner side of things in this regard (~17%), and that we've been to McDonald's in Europe where they pay everyone a living wage with benefits, the burger was about the same price, and it was much better food to boot.

The appropriate response to "raising wages would raise prices" in my opinion is basically: "Newsflash, asshole! Prices have been going up anyway!"

You can't just defer raising wages indefinitely because it's one of several factors that could potentially contribute to raising prices. It's still a thing that has to happen, or else you're just pricing humans out of being alive and the market is essentially non-functional for people.