Highly suggest you read Apple developer docs. iOS suspends apps in the background but can save app state to storage (kind of like suspend to disk on laptops). Android, on the other, can keep apps running in the background for things like media/file/web server. So, it's false to say that Android is unoptimized. That doesn't make any sense like saying Mac is unoptimized compared to iPod.
So true, which is why I had so many issues with cloud apps uploading in the background. I had to open them to finish uploading.