Not everyone can take orders in a drive-thru and most people take weeks to become proficient speaking publicity and familiarizing themselves with the menu and customer slang. It takes months or even years to become remarkably good at it. Many people can take orders in a drive-thru just like many people can become engineers and surgeons. The disconnect lies in that not many people have the time or resources to get a specialized education or they're ignorant and can't learn because their entire social circle is ignorant. There would be significantly more engineers and surgeons if there were a surplus of on the job training opportunities like there are for drive-thru positions.