> From minor things like “iOS Safari won’t let you play audio without first interacting with the page” to major, show-stopping things like, “iOS Safari won’t let you play the next song if your app is in the background or if your screen is off.”

Ugh... these are the sort of capabilities that I think people don't realize are often misused. iOS has been good about being pro-consumer first. This missing feature in iOS Safari is intentional for that reason.