According to this [1] (first thing I was able to find, no clue how accurate): Another major cost for McDonald’s is payroll and employee benefits. These account for 36% of its company-operated restaurant expenses.
I don't know in what world a third is "only a small part". The same article mentions According to PayScale, the average worker in the fast-food industry makes $8.50 per hour. Increase that to $44 and you end up with a much more expensive burger.
The article you link fails to mention that McDonald's also spent about 8.5 billion on stock buybacks and dividends in 2018, which would have been enough to give every one of their 210,000 employees an extra 40,000 dollars that year on top of what they already made that year. Not quite $44 an hour, but a hell of a lot better than minimum wage - and the company wouldn't need to spend a single extra cent or raise any prices in order to do it.
