McDonalds might be premium compared to a roadside food stall, but it's on the low end of the spectrum in first world countries. Anywhere I have traveled, McDonald's was just the emergency option if you just really needed food that wouldn't give you food poisoning.

Also, poor people absolutely eat there. All those poor people working there get free food and employee discounts, others use the app, or they eat there once in a while as an alternative to more expensive restaurants.