Those jobs are low skill and arguably for children and youth, adults looking to McDonalds for serious employment should probably go check into a mental health facility if they are not applying as a manager.
Litterally anyone who didn't just graduate or crawl out of a proverbial hole, would have more skill than the pay grade at McDonald's and raising the pay will not produce a better experience for the consumer who is the most important part of the business.
I would agree if it wasn't 56% of American wokers that earn minimum wage... and you are right the customer experience is important, but there's a difference between the purpose of a job and the purpose of a business. Earning a living and making profits are not incompatible and that's what the Danes are showing us.
Laborers are just cogs in the machine. The economy can only support what it can support. You can not pay more than your GDP allows. Yes CEOs are greedy, but then again, if you are calling them greedy, we can call minimum wage workers stupid for working for such a low rate.