You're assuming McDonald's has a much higher profit margin than it actually does - it's a restaurant chain, not a software company. In other words, the wages for the guy making the burger isn't the only input to cost. E.g., if the beef in that $2 burger used to cost $0.50, it might cost $0.75 now, partly as a response to the need for the farmer to pay himself more. There's also the people working at the meat processing plant, everything that went into the bun, the transportation costs, marketing costs, etc.
Also, I am only going to pay so much for a McDonald's sandwich before I decide the cost to quality ratio is too high, and either make it myself or go to a restaurant that has a better cost to quality ratio.
I find the making it myself option to be much better due to the increased volatility of quality. Sure, I might spend 2 hours cooking and cleaning, but I know the quality will be good 100% of the time, whereas spending $25 per person may or may not get me a decent meal because the restaurant does not have steady employee and/or is cutting corners on quality ingredients to make up for other cost increases.
I think this would hurt the middle restaurants more than McDonalds though. McDonald's has it all streamlined so they can manage costs and still delivery consistency at a low price, but the restaurants in the middle that are okay, but not top tier no longer make sense.
> I find the making it myself option to be much better due to the increased volatility of quality.
I am not a good cook, but I did learn to cook the things I like to eat out specifically because of this consideration. In the beginning, it was a more difficult decision, but now I wouldn't for the world trade my certain home cooked dishes for restaurant ones.
